Uchenna Chiedu
$11/hr
I am an information technology specialist and project manager
- Reply rate:
- -
- Availability:
- Full-time (40 hrs/wk)
- Age:
- 37 years old
- Location:
- Isolo, Lagos, Nigeria
- Experience:
- 8 years
Deploying a VoIP Based system over a Secured
WLAN in a care home using 3CX
By
UCHENNA CHIEDU
-)
A Project Dissertation submitted in partial fulfilment of the
regulations governing the award of the degree of M.Sc. in
University of Sunderland JAN 2014
Project Supervisor: PHILIP IRVING
Abstract
Over the last decade Wireless Local Area Network (WLAN) has gained success in hospitals
and care homes. However, wireless networks still remain an area of research to exploit, as it
gives mobility characteristics to applications. In the continuous development and
enhancement on WLAN, it has been seen that the healthcare sector are taking advantage of
it characters by deploying real-time application on WLAN. Now with the advent of the Voice
over internet Protocol (VoIP) another real-time application that has saved a lot of
organizations cost contrary to the Public switch telephone Network, because it provides a
cheaper means of communication through carrying voice over organizations’ already
existing Internet Protocol networks. The deployment of WLAN in organizations has seen the
emergence of VoIP over WLAN or referred to as VoWLAN for further support for mobility.
In the health sector, VoWLAN is readily used to assist in healthcare operation, for Voice call
services, tracking and surveillance. VoWLAN used in care home facility require mobility
functions to enable worker move while having conversation, also this calls should have clear
quality in order to meet needs of callers.
This project is aimed at delivering a low-cost means of communicating via VoIP over WLAN
for a care home to support staffs voice mobility and also guarantee voice quality. The
VoWLAN system in this project is secured by protecting devices and users of the wireless
LAN through a Remote Access Dial in User Service (RADIUS) server and the Cisco Centralized
Key Management (CCKM). Also the project seeks to research the needs VoIP fulfils in a care
home and its advantages. This project also focuses on research on VoIP and WLAN
technologies required to support roaming, security and Quality of service for the
development of Phone system on WLAN for a care home.
In this project an analysis was provided on how devices roamed within access points. A
simulation was carried out to see that voice roaming is capable. The simulation showed that
the WLC indicated that a device roamed from one access point to another during a Voice
call. Several test verification was done to analyse and certify the functions of the VoWLAN
system.
i
Acknowledgments
I want to thank the Lord God Jesus Christ for grace to start and successfully complete this
project. I want to also thank God for life to attend the University of Sunderland that gave me
the knowledge and skill to embark on this project.
I am grateful to my family who sacrificed their little earnings to enable me further my
education to a master level. My father and mother, Mr and Mrs Chiedu, I want to use this
medium to say thank you for all your support. I am also thankful to my siblings and in-laws; I
remain loyal to you all.
I want to use this medium also to acknowledge Mr Philip Irving my supervisor, for all the
guidance, advice, technical supervision and instructions during the course of the project
which saw me through to the end of this project. You were always available even off
supervisory time. I also want to thank you for the soliciting for me during the period of my
illness.
I want to thank the sponsor of the project for all the support and dairies and papers used
effectively during the research. I would to thank my Tutors in the Telecommunication
Engineering programme in the University of Sunderland, particularly Mr David Evans, Mr
Stephen Swales and Bernie because what you taught me was used in this project.
I want to thank all my friends for their support and encouragement, Adaobi, Pascal, KC,
Darlington, Ibrahim, Akachi, Miss Kerry and Tade. I want to also thank all those that
volunteered in partaking in the MOS test.
Finally, I want to thank everyone that supported me all through the project. I want to say
Thank you.
ii
Contents
Abstract ............................................................................................................................ i
Acknowledgments ............................................................................................................ ii
LIST OF TABLES ................................................................................................................ ix
List of FIGURES ................................................................................................................. x
INTRODUCTION ................................................................................................................ 1
1.1 Project Overview ..................................................................................................... 1
1.2 The Client .............................................................................................................. 1
1.3 Need for Project ...................................................................................................... 2
1.4 Client Requirements ................................................................................................ 2
1.5 PROJECT OBJECTIVES ............................................................................................... 2
TABLE 1.2 project objective .............................................................................................. 2
1.6 RESEARCH METHODOLOGY ..................................................................................... 3
Project Chapter structure .............................................................................................. 3
VoIP over WLAN Relevance in Fulfilling Communication Needs in Old People’s Home ....... 4
2.0 INTRODUCTION ....................................................................................................... 4
2.1 The client ................................................................................................................ 4
2.3 The client’s need ..................................................................................................... 4
2.4 Communication Technology that satisfies client’s need ............................................ 4
2.5 Care home communication approach....................................................................... 5
2.5.1Face to face to conversation: ..................................................................................... 5
2.5.2 Phone calls ................................................................................................................. 5
2.5.3 E-mail: ........................................................................................................................ 5
2.6 Critical Analysis of Client’s needs for VoIP over WLAN in old People’s home............. 6
2.6.1 Seamless Call During mobility and work activity of staffs ......................................... 6
2.6.2 Emergency control..................................................................................................... 6
2.6.3 Catering for the Challenged wards: ........................................................................... 6
2.7 VoIP telephone features that can be delivered in our client Old People’s Home ....... 6
2.7.1 Auto attendant .......................................................................................................... 7
2.7.2 Call Distribution (CD): ................................................................................................ 7
2.7.3 Call Recording ............................................................................................................ 7
2.7.4 Call Conferencing ....................................................................................................... 8
2.7.5 Voicemail ................................................................................................................... 8
iii
2.8 Conclusion............................................................................................................... 8
CHAPTER 3 ....................................................................................................................... 9
REASSESSING VoIP over WLAN ......................................................................................... 9
3.0 Introduction ............................................................................................................ 9
3.1 Concerns of VoIP on WLAN ...................................................................................... 9
3.1.1 Quality of service and system capacity issues: .......................................................... 9
3.1.2 Security and Admission control: .............................................................................. 10
3.1.3 Roaming/ Hands-off Issues: ..................................................................................... 11
3.2 Benefits of WLAN to Client Network ...................................................................... 11
3.3 REVIEW ON WIRELESS LOCAL AREA NETWORK (WLAN) .......................................... 11
3.3.1 Overview of WLAN................................................................................................... 11
3.3.1A WIRELESS LAN TECHNOLOGIES ............................................................................. 12
3.3.1B WLAN components ................................................................................................ 12
3.4 WIRELESS LAN TOPOLOGIES .................................................................................. 13
3.5 Recommendation .................................................................................................. 15
3.6 VOIP ARCHITECTURE ............................................................................................. 15
3.7 THE 3CX VoIP Server .............................................................................................. 15
3.8 Codecs .................................................................................................................. 16
3.9 VOIP PROTOCOLS .................................................................................................. 17
3.10 Signalling Protocols That Can Be Deployed on Client VoIP Server: ........................ 17
3.11 Recommendation ................................................................................................ 18
3.13 MEDIA PROTOCOLS ............................................................................................. 18
3.14 VOIP SECURITY .................................................................................................... 19
3.15 The Integration of VoIP to WLAN ......................................................................... 19
3.16 Roaming/Handover ............................................................................................. 19
3.17 According to (Cisco, 2011), the 802.11r gives the basic support for roaming ......... 22
3.18 KEY TERMS OF ROAMING PHASES ........................................................................ 23
3.18.1 Scanning................................................................................................................. 23
3.18.2 Authentication ....................................................................................................... 24
3.18.3 Association............................................................................................................. 24
3.19 Client’s premises ................................................................................................. 24
3.20 Client’s Present network ...................................................................................... 24
3.21 Client’s VoWLAN needs ....................................................................................... 24
iv
3.22 Client’s Telephone system and Network issues .................................................... 24
3.24 Recommended solution ....................................................................................... 25
3.25 MOBILITY DECISIONS ........................................................................................... 25
3.26 VOICE AND ROAMING ......................................................................................... 27
3.27 QUALITY OF SERVICE SPECIFIC FOR (VoWLAN) ..................................................... 27
3.27.1 Best Effort Network Model.................................................................................... 28
3.28 QOS DEPLOYMENT FOR CLIENT’S VoIP NETWORK ................................................ 28
3.28.1 Integrated Service Model ...................................................................................... 28
3.28.2 Differentiated Services Model ............................................................................... 28
LAYER2 QoS....................................................................................................................... 28
Layer 3 QOS ...................................................................................................................... 28
3.29 QoS MODEL INBOUND OPERATION...................................................................... 29
3.29 Queuing Mechanism ............................................................................................ 30
3.30 QoS ON WLAN ..................................................................................................... 30
Chapter 4 ....................................................................................................................... 33
Prototype Design chapter ............................................................................................... 33
4.1 Introduction .......................................................................................................... 33
4.2 Client Requirement ............................................................................................... 33
4.3 Network Design approach ..................................................................................... 33
4.4 Network Structure Design (Logical structure) ......................................................... 33
4.5 WLAN Network Design .......................................................................................... 34
4.6 The Telephone 3cx server ...................................................................................... 35
4.7 Design for Roaming. .............................................................................................. 35
4. 8 Justification for Network design............................................................................ 38
4.9 Proof of design Concept......................................................................................... 38
4.10 Telephone system design..................................................................................... 40
4.10.1CODEC ..................................................................................................................... 40
4.10.2Signalling Protocol .................................................................................................. 40
4.10.3 Dial Plan Design ..................................................................................................... 40
4.10.4 Telephone features design .................................................................................... 40
4.11 Design for WLC .................................................................................................... 40
4.11.1 Security of Wireless LAN........................................................................................ 40
4.12 WLAN QoS Design................................................................................................ 41
v
System Implementation ................................................................................................. 42
5.1 INTRODUCTION ........................................................................................................ 42
5.2 Network Implementation ...................................................................................... 42
5.2.1 Routing configuration: ............................................................................................. 42
5.2.2 Trunking configuration ............................................................................................ 42
5.2.3 DHCP server configuration ...................................................................................... 43
5.2.4 Switch Configuration ............................................................................................... 43
5.2.5 WLC configuration ................................................................................................... 44
Fig 5.5: WLC configuration................................................................................................ 45
5.2.6 Access Point Deployment ........................................................................................ 46
5.2.7 WLC interface configuration .................................................................................... 46
5.3 Roaming configuration .......................................................................................... 50
5.4 Security Configuration for wireless LAN ................................................................. 51
5.4.1Radius server ............................................................................................................ 51
5.4.2 Further security ....................................................................................................... 55
5.5Configuration for VoIP ............................................................................................ 55
5.5.1 Configuring of extensions on the phone system ..................................................... 55
5.5.2 Configuring SIP client ............................................................................................... 56
5.5.3 Configuring PBX Telephone features ....................................................................... 57
5.6 WLAN QoS Implementation ................................................................................. 58
5.7 Work station and device configuration .................................................................. 60
CHAPTER 6 ..................................................................................................................... 62
6.0 TESTING .................................................................................................................... 62
6.1 Network connectivity test ..................................................................................... 62
6.2 Telephone Verification .......................................................................................... 65
6.2.1 Call setup ................................................................................................................. 66
6.2.2 To verify the SIP to SIP call session ......................................................................... 66
6.2.3 Verification of Auto-Attendance /Digital reception ................................................ 67
6.2.4 Voicemail ................................................................................................................. 68
6.2.5 Group ring ................................................................................................................ 69
6.2.6 Call Queue/ Call distribution ................................................................................... 69
6.2.7 Call conference ........................................................................................................ 70
6.2.8 Call recording ........................................................................................................... 71
6.2.9 Video call ................................................................................................................. 71
6.3 ROAMING TEST ..................................................................................................... 72
6.3.1 Second test for roaming .......................................................................................... 75
vi
Security testing ........................................................................................................... 76
6.22 Verification of SRTP ............................................................................................. 77
6.23 Testing WLAN QoS ............................................................................................... 78
6.23.1 Link Congestion ..................................................................................................... 78
6.23.2 before QoS Implementation .................................................................................. 79
6.23.3After QoS ................................................................................................................ 80
6.24 ISSUES ENCOUNTERED ......................................................................................... 80
6.25 RESULTS .............................................................................................................. 82
CHAPTER 7: EVALUATION ............................................................................................... 83
7.1 CHAPTER INTRODUCTION ...................................................................................... 83
7.2 Evaluation on the prototype .................................................................................. 83
Client Requirement 1 ........................................................................................................ 83
Client requirement 2 ........................................................................................................ 83
Client requirement3 ......................................................................................................... 83
Client requirement 4 ........................................................................................................ 84
7.3 Evaluation on Project Objectives ........................................................................... 84
Objectives1: ...................................................................................................................... 84
Table 7.1 evaluation table .............................................................................................. 84
Objective 2 ........................................................................................................................ 84
Objective 3: ....................................................................................................................... 85
Project objective 4: ........................................................................................................... 85
Projective objective 5: ...................................................................................................... 85
Project Objective 6: .......................................................................................................... 86
Project objective 7: ........................................................................................................... 86
CHAPTER 8: PROJECT SUMMARY AND FUTURE ............................................................... 87
RECOMMENDATION ....................................................................................................... 87
8.1INTRODUCTION ...................................................................................................... 87
8.2 Project conclusion ................................................................................................. 87
8.3 Recommendation for future Research ................................................................... 87
Reference ....................................................................................................................... 88
LIST OF ABBREVIATION ................................................................................................... 94
APPENDIX A ................................................................................................................... 95
1ST REVIEW ASSIGNMENT ........................................................................................... 95
APPENDIX B.................................................................................................................. 106
vii
Client Feedback form ................................................................................................ 106
MOS SHEET ............................................................................................................... 126
APPENDIXC
…………………………………………………………………………………………………………………………...137
THE LAYER3 SWITCH Configuration............................................................................ 138
Layer2 switch ............................................................................................................ 139
WLC CONFIGURATION ............................................................................................... 140
3CX PHONE SYSTEM CONFIGURATION ....................................................................... 141
viii
LIST OF TABLES
TABLE 1.1 client requirement ............................................................................................ 2
TABLE 1.2 project objective ............................................................................................... 2
Table 3.1 showing Wireless standards adopted from Nortel.com ...................................... 11
TABLE 4.1 DESIGN TABLE ................................................................................................. 33
TABLE 4.2 DHCP SCHEME................................................................................................. 39
TABLE 4.3 SERVERS ......................................................................................................... 39
TABLE 4.4 WIRELESS NEWORKS ....................................................................................... 39
TABLE 4.5 VLAN .............................................................................................................. 39
TABLE 4.6 TELEPHONY FEATURES..................................................................................... 40
TABLE 6.1 MOS ............................................................................................................... 78
TABLE6.2 result ............................................................................................................... 82
Table 7.1 evlauation table ............................................................................................... 84
ix
List of FIGURES
Figure 3.1 showing Access Point: (Motorola) 2005 ............................................................ 12
Figure 3.2: Wireless LAN Controller. Source: (Cisco, 2011)................................................. 13
Figure 3.3: The Basic Set Service. Adopted from TX.COM google (2006) ............................. 14
Figure 3.4: The Extended Set Service. Adopted from Google Nortel (2002) ........................ 15
Figure 3.5: Centralised VoIP Architecture. Adopted from (Chava & Ilow, 2007) .................. 17
Figure 3.7 SHOWING ROAMING. Adopted from APTECH Engineering.org (2010) ................ 20
FIG 3.8 Adopted from Cisco, 2010, roaming between access point. REF CISCO.COM .......... 21
FIG3.9 Showing INTER access point Adopted from Cisco.sunderland.ac.uk. ........................ 22
FIG 3.11 Overlap of cells with channel non-overlap, Adopted from CISCO, 2009 FROM
CISCO.COM ..................................................................................................................... 25
FIG 3.12 QoS classification (Cisco, 2008) SHOWING LAYER2 AND LAYER3 CLASSIFICATION
(PACKETS AND FRAMES) .................................................................................................. 29
FIG3:14 showing WMM Queues....................................................................................... 31
FIG3:15 showing timE waiting interval WMM Queues ....................................................... 32
FIG 4.1 SHOWING WLAN AP deployment Cisco, 2011........................................................ 37
FIG5.1 routing configuration, Chiedu, 2013 ...................................................................... 42
FIG5.1 Trunking configuration, Chiedu, 2013 .................................................................... 42
FIG5.3 DHCP router configuration, screen shot, Chiedu, (2013) ......................................... 43
Fig 5.4: Switch configuration showing allocation of ports on the switch. ............................ 44
Fig 5.5: WLC configuration. .............................................................................................. 45
Fig 5.6: WLC configuration. .............................................................................................. 46
FIG 5:7: showing the connected access point on the WLC monitor .................................... 46
FIG 5:8 showing the created interface on the WLC for voice .............................................. 47
FIG 5:9 showing the IP address information of the voice interface. .................................... 47
. FIG 5:10 showing the Different interfaces on the WLAN .................................................. 48
FIG 5:11 creating new profile network ............................................................................. 48
FIG 5:12 Navigation to creating new profile ...................................................................... 49
FIG 5:13 creating profile for voice and SSID ...................................................................... 49
FIG 5:14 creation of policy on the SSID ............................................................................. 49
x
FIG 5:15 LIST of SSIDs ...................................................................................................... 50
FiG 5:16 client roaming configuration .............................................................................. 50
This Fig5:17 shows that a certificate has been created for users ........................................ 51
This Fig5:18 shows shared secret between RADIUS and WLC ............................................ 52
This Fig5:19 Graph show creating user information. ......................................................... 52
FiG5:20 showing 802.1X CONFIGURATION........................................................................ 53
FIG5:22 Using INSSIDER software to Analyse available networks ....................................... 54
FIG5:23 securing sip client ............................................................................................... 55
FIG5:24 configuring extensions ........................................................................................ 56
FIG 5:27 configured features on 3cx server ....................................................................... 58
Fig 5.28 QoS INTERFACE CONFIGURATION FOR AP ON SWITCH ......................................... 59
Fig 5.29 QoS INTERFACE CONFIGURATION ON WLC FOR VOICE INTERFACE ....................... 60
Fig 5.30 DEVICE REGISTERED WITH WLC ........................................................................... 61
FIG: 6.1 showing network connectivity to the interfaces on the Network ........................... 63
FIG: 6.2 showing network connectivity to service interfaces and server on the Network .... 64
FIG: 6.3 showing 802.11 protocol running ........................................................................ 65
FIG: 6.4 showing SIP phones have been registered in VoIP server showing client device IP
address........................................................................................................................... 66
FIG: 6.7 digital reception/ auto attendant verification ....................................................... 68
FIG: 6.8 voicemail verification .......................................................................................... 69
FIG: 6.9 Group ring verification ........................................................................................ 69
FIG: 6.9 call queue verification ......................................................................................... 70
Fig 6.11 call recording verification .................................................................................... 71
Fig 6.12 video call verification .......................................................................................... 72
Fig 6.14 shows MAC address of devices associated with the LWAP1. ................................ 73
Fig 6.16 shows MAC address 90:a4:de:76:4b:89 is now on LWAP2 and moved from LWAP1
...................................................................................................................................... 74
Fig 6.17 SHOWS SIGNAL STRENGTH DURING ROAMING FROM 1ST ACCESS POINT TO THE
NEXT ACCESS POINT ........................................................................................................ 75
Fig 6.18 shows the AP and the devices associated to it before roaming ............................. 75
Fig 6.20 call session ......................................................................................................... 76
xi
Fig6.21 RADIUS server verification ................................................................................... 76
Fig 6.22 shows that SRTP verification has not been implemented ...................................... 77
Fig 6.23 shows that SRTP verification has been implemented ............................................ 77
FIG 6.25 JPERF SENDING TRAFFIC ON THE WIRELEESS LINK ............................................... 79
FIG 6.26 SUMMARY OF CO-CHANNEL INTEFERENCE ......................................................... 81
FIG 6.27 SHOWING CO-CHANNEL INTERFERENCE UPDATE ................................................ 81
TABLE6.2 result ............................................................................................................... 82
xii
INTRODUCTION
1.1 Project Overview
The advancement and the deployment of 802.11 which is WLAN have its popularity
increasing by the day. The WLAN is not just an alternative to wired network; they are
prospective infrastructure to deliver mobile broadband internet services. Typically Wireless
Local Area networks on any of the IEEE802.11a/b/g/n are the standards which are broadly
deployed round the globe known as WI-FI meaning Wireless Fidelity. Most school campuses,
hospitals and organizations are deploying wireless Local area network because of numerous
devices such as smart phones that are used by end users in the network.
Voice over Internet Protocol (VoIP) has become a house hold name amongst the various
Internet applications. VoIP is an emergent technology that is taking over regular traditional
public telephone systems as an alternative as result of its cost effectiveness accompanied
with high resource Utilization. According to (Khan & Ong, 2008), typically most organization
maintains two different networks for data and voice. However, VoIP has saved cost for
organization because it allows both data and voice traffic in one network, which drastically
saves cost for organization. This uniqueness of VoIP has made different sector seek its
deployment even down to health care. In line with (Rosati, 2009) VoIP uniqueness also calls
for proper management since different traffic exists in a single network. VoIP deployment
on wired networks has its limitations, as it does not support mobility during voice calls.
Nowadays VoIP services are been deployed on WLAN, because of mobility characteristics of
WLAN. WLAN typically was designed to transport data; but with voice, proper enhancement
is needed to attain voice quality.
The VoIP over WLAN which may be also referred to VoWLAN may serve different purpose
for different establishment. The air medium in which WLAN operates which makes voice
and data mobile and needs to be properly managed so that application like voice won’t be
compromised during roaming. Likewise because of the inherent characteristics of WLAN,
adequate measures are to put in place to guarantee voice quality during calls. Hence, the
terms of reference proposal of this project is to develop a VoIP over WLAN system that is
owns mobility functions and derives good voice quality.
1.2 The Client
The client is a Care Home located in Nigeria; however the sponsor wants to remain
anonymous. The client’s organization is a place where persons’ or old people who are
incapable of taking care of themselves reside. These old people are kept in care home so
that they can be taken care off. The client’s care home has less than 50 staff taking on
different activities in the building. The client is looking for a different means of improving
communication so as to boost productivity in his organization.
1
1.3 Need for Project
Care home require high interaction. However, communication in the care home has been
suspected by the sponsor to be low level. The sponsor stated that PSTN lines are deployed
in the care home, but mentioned the high cost of maintaining them and also having limited
telephone features and thus seeks cheaper alternative. Deploying VoIP on WIRED network
will still restrict mobility as staff in the care home facility may need to attend to ward calls
while moving from one ward room to another in the care home. The care home has
identified VoIP over WLAN because it will enable call mobility to allow staff in the care
facility move round the care home facility attending to calls from wards and other activities
that meet the care home needs. Hence this project is embarked on to prove the concept of
voice mobility on WLAN and attaining voice quality.
1.4 Client Requirements
The requirement set out by the client
Client Requirements
An Implemented VoIP system on secured a Wireless LAN capable of call
functionality within the Care home office premises
Research VoIP over Wireless network
Evaluate design and build a prototype VoIP system
Evaluate the prototype as regards to Quality of Service
TABLE 1.1 client requirement
1.5 PROJECT OBJECTIVES
The project objectives is in the table below
OBJECTIVES
1 To research features in VoIP over WLAN relevant to deliver communication
needs in old people’s home.
2 review literatures on roaming with QoS within access points on WLAN
3 Design and implement a roaming prototype VoIP system over WLAN using 3CX
4 Test prototype for roaming and Voice quality and operability
5 evaluate prototype on best industry standards
6 Give recommendation for future improvement
7 To Present dissertation
TABLE 1.2 project objective
2
1.6 RESEARCH METHODOLOGY
For quality research, the project objectives are to have a well-structured approach which is
needed to accurately carry out the project. The use of peer reviewed journals from wellknown telecommunication, computing, information technology organizations and society
such as Institute of Electrical and Electronics Engineers, Engineering Village, Internet
Engineering Task Force (IETF), International Telecommunication Union (ITU), science direct,
Google scholar, and white papers from organization such as 3cx, Cisco and online journal
site like safari online. Also the university library is useful, with notes and tutorials from the
Telecommunication Engineering program
Project Chapter structure
The breakdown of the dissertation is the bullet point below
Chapter1 introduces the project scope in an overview
Chapter2 researches the needs VoWLANs fulfils in a care home.
Chapter3 reassesses VoIP over WLAN, with critical analysis on mobility and quality of
service for WLAN.
Chapter4 presents the design from which the VoWLAN system will be built with the
knowledge gain from the research chapters
Chapter5 is the implementation of the roaming VoWLAN built from the design
Chapter6 is testing and verification of the implemented system
Chapter7 gives critical evaluation of the VoWLAN system and the project in whole
Chapter8 concludes the project with adequate recommendation for future research
3
VoIP over WLAN Relevance in Fulfilling Communication Needs in
Old People’s Home
CHAPTER 2
2.0 INTRODUCTION
Caring can be described as the task of taking care of individuals that are incapable of fully
taking care of themselves. A person who looks after old people, physically challenged
persons or even children is described as a Carer (McDonnel & Grimson, 2010). Wards are
persons that are been taken care of in the care home. In order to increase work
productivity, this carer especially the ones in old peoples’ homes need to be able to
communicate effectively and efficiently. Employing telecommunication technology in the
health and care environment has brought about the term ‘’telemedicine’’, which means use
of telecommunication to offer medical services and information (Taylor & Wilson, 2009).
Wireless telemedicine which is typically termed “mobility health” takes advantage of the
features WLAN technologies possess for effective care delivery in old people’s home
(Teymoori & Mousavi, et al 2009).
2.1 The client
The project sponsor runs a care home (old people’s residence). The sponsor’s business is
made up of supervisors, carers and wards.
2.3 The client’s need
The project sponsor is in need of a reliable and cost effective way to communicate via voice
within the care home facility. The client has identified the need for close interaction
between carers, supervisors and ward. The client is looking at a means of voice
communication to enable workers roam round the building and attend to their duties.
2.4 Communication Technology that satisfies client’s need
As (Cook & Clark et al, 2009) observed, typical care home that rely less on communication
technology witness lower level of interaction because they could be issues of slow response
from carers to react on time to need of wards. However, (Rosati, 2009) asserts that because
of demanding interactive nature of care homes, a readily available means of communication
is needed to meet the needs of caring and monitoring of wards. These available means of
communication according to (Lin, Chiang et al) must create a network between carers,
supervisors and wards in the care home. While (Volner &Smrz) points out that the 2 ways to
communicate via technology networks in care home are through wired networks and
wireless network communication in care home. However, (Robinson & et al, 2007) opined
that wired local area networks are more reliable and secured networks for care homes than
the wireless Local area networks. According to (Menkens & Kurschl, 2007), though wired
network is more secure than wireless LAN, wireless LAN meets 90% of the requirement
needed in a care home because of the infrastructural connection WLAN brings to support
4
mobility, real time application like Voice Over Internet Protocol will aid carers and
supervisor in our client’s care home premises to interact through voice calls and react to
emergency calls (McDonnel & Grimson, 2010). Also, other real time application like tracking
and monitoring system assists in supervising patient and even keeping tabs on carers and
wards movement (Taylor & Wilson, 2009). Furthermore, Wireless LAN also support
handling and transfer of data file of patients within the care home (Llal, 2006). (Shirley & et
al, 2012) summarises that VoWLAN has a huge role to play in old people’s home to
effectively address the high level interaction needed between wards and carers as well as
other required communication functions.
2.5 Care home communication approach
Communication technology is critical to the success of a quality care home for old people
(Lin, Huang & Chang, 2008). This author further believes that VoIP over WLAN
communication services meets the requirements and ensures a reduction of errors that
happen in a care home and thus provide better management in old people’s home. There
are different ways in which wards and carers communicate or carers and supervisors
communicate within the old people’s residence. These means of communicating within the
premises may be through face to face conversation, emails and phone calls.
2.5.1Face to face to conversation: This is the oldest means of communication. The Carers
best means of communication to wards in old people’s home is through this medium as it
entails that they have to see their wards face to face to know exactly how they faring (Kaza
& Asadullah, 2006). Also physical contact with care home supervisors is imperative as
seeking some particular kind of information may require face to face meetings. However it
should be noted that face to face conversation is not always possible because of Carer may
not be available at every given time.
2.5.2 Phone calls: Phone calls between carer and supervisors or carer and ward are very
necessary for interaction, as phone calls are distant communications in real-time. Using
PSTN old PBX installed within the old people’s home premises will incur high maintenance
cost for calls within the premises which incurs more cost as compared to using a VoWLAN
solution (Chiang & et al, 2008).
2.5.3 E-mail: In this technological savvy world, this is the most common means of
communication adopted by most organizations (Shirley & et al, 2012). Emails are used in
most organizations to exchange information within staffs and customers but in the context
of this paper, the client’s organization would use Email for sharing information amongst
carer and supervisor. E-mailing has been recognised as a dependable means of
communicating and also less expensive for organisations. However, in line with old people’s
home interaction, emailing may not provide automatic response to emergencies when such
situations arise (Cai & et al, 2006).
5
2.6 Critical Analysis of Client’s needs for VoIP over WLAN in old People’s
home
According to (Teymoori & Mousavi, 2009), deploying VoWLAN is more expensive than the
deployment of a wired VoIP. However, this author also acknowledges that in a rundown, the
added benefits such of the ease of deployment, flexibility of communication and mobility
characteristics WLAN brings to VoIP makes it a cost saving solution. Hence, the various
needs for VoWLAN in residence of old people are;
2.6.1 Seamless Call During mobility and work activity of staffs: For the client’s old people
home residence, VoWLAN will enable carer and supervisors to efficiently respond and react
to verbal instruction even when having other duties being attended to and this is because
even when moving they can attend to duty calls from wards within premises and keep in
contact with supervisors. As observed with cases of using cellular phones, sometimes
interruptions and problems of no or low signal strength may arise which compromises
communication between carers and supervisors (Ghorbel, Arab, & Mokhtari, 2008).
VoWLAN gives supports to enable server based applications, giving Carers spot-on access to
wards data which is usually needful for good quality care of ward and effectiveness of carer
(Teymoori & Mousavi, 2009).
2.6.2 Emergency control: According to (Ghorbel, Arab, & Mokhtari, 2008), VoWLAN
supports features like push-to-talk on VoIP phones which will enable wards in the old people
home give broadcast alert to call attention of carer, though carer may be moving and may
not be at a close range to the ward. The to Push-to-Talk application bring to carer’s notice
that a ward needs attention, which leads to complete satisfactory care of wards in the
client’s care home (Shirley & et al, 2012).
2.6.3 Catering for the Challenged wards: As demonstrated by (Shirley & et al, 2012), the
Voice text application which is a feature in VoWLAN will aid communication between carer
and wards that may be hard of hearing in old people’s home especially when the carer may
be attending to other activities at some distance from the ward.
2.7 VoIP telephone features that can be delivered in our client Old People’s
Home
VoIP major features will mainly be explored within the internal network of our client’s care
home network which will provide viable voice service and extra features to users within the
network. As (Menkens & Kurschl, 2010) suggests, calls centre with rich features improves
the quality of communication in the care home. Asides from basic functions of calls
conversation, features like group ring, voice mail, call distribution, call recording, call
automated attendance and call blacklisting and can be seen in 3CX IP PBX.
These listed VoIP features are of relevance to care home for old people and will be
discussed below.
6
2.7.1 Auto attendant: as demonstrated by (Korchi & et al, 2008) This is referred to as menu
system and functions as an automatic system that is employed for accepting calls that are
incoming and give assistance to a caller as it processes routing of the call to the intended
receiver. In the client’s premises, the menu system is employed which is used to redirect
calls to the desired Carer when the next of kin of a ward in the premise would want to speak
to the carer of the ward during non-visiting hours (Kaza & Asadullah, 2006). Auto attendant
(menu system) functions like a helpdesk admin or a receptionist who attends to request of
callers by requiring relevant information from caller so as to find out who the caller would
want to speak to in the organization, and therefore aid the caller by forwarding the call to
the desired person. Within the old people’s residence, the auto attendant normally
welcomes the caller (ward or ward next of kin) with some form of greetings and will the
push the caller to making selection of the available options by making use of the numbers
on the keypad. It can occur in scenarios, for instance; for Carer1, press 1, for supervisor1,
press 2, for Carer2, press 3, for Carer3, press4, for supervisor2, Press 5. The selected option
will route the call straight to the intended carer or supervisor or ward. (Motorola, 2012)
recommended the AA combination with a voice recogniser application which enables
creation of a user friendly interface, having the users orally select the desired menu rather
than hitting the number on the phone’s keypad. This is a less pricey application that can be a
deployed system on 3cx IP-PBX software (3CX, 2010).
2.7.2 Call Distribution (CD): Call Distribution is a method employed to manage incoming
calls. As explained by (Motorola, 2011), call distribution is used to reduce the weight of
inbound call to the care home, by distributing calls to next supervisors readily available. In
situations where individuals want to speak to supervisors and have queue loads, call
distribution takes of pressure from the PBX, by forming call queue which is employed to
accumulate groups of calls, keep them on hold and allot them to the available supervisor or
carer. Described by (Baharlooei & Hashemi, 2009) (typically for call distribution, different
methods of ranking and priority stakes will be implemented on call queue such as if the calls
for a supervisor will have more priority than that of carer or vice versa. Call distribution is
mainly beneficial in cases where callers have less need to talk to a particular individual
within the old peoples’ home but want quick assistance on information concerning care
home (Subalakshmi & et al). Further emphasis by (3CX, 2010) shows that by employing IPPBX software like 3CX, lots of features could be integrated in a VoIP infrastructure to
properly manage inbound calls at a contact centre.
2.7.3 Call Recording: (Cook & Clark et al, 2009) explains that Typically this feature is for
quality assurance purposes and to help improve on customer relations as it records and
monitor real-time voice conversation as it passes through the VoIP server such as 3CX. This
is extremely useful in the old peoples’ home call system dial plan as recorded conversation
can be used to train newly employed Carers (Motorola, 2011). Another use of call recording
in old people’s home is to administer fairness in care between carers and wards. In an old
people’s home like that of the client; since the wards is the first point of reference they
7
deserve all the attention, so conversation recording may be used to check if wards are being
responded to in a polite and hospitable manner. Generally is good for use assessing carers
and wards (Sung, Y., Lin,Y., 2008).
2.7.4 Call Conferencing: It is another feature that can be seen with the VoIP system that can
support multiple persons to have conversation in one call or even video, as if they are
physically present in conference room. It is a feature offered by the 3CX software PBX (3CX
2010). Discussion will mean that within the old people’s home, the internal phone system
can offer call conferencing features which can be used for brief meetings between carers
and supervisors.
2.7.5 Voicemail: Voicemail is a telephone feature that has been there for some time now.
Voicemail features permits callers to record voice messages for calls that weren’t answered
either by phone set being off or out of network area or may be the intended number is
busy. (Cisco, 2009) pointed out extra features could be deployed in organization IP-PBX
system such that the IP-PBX are able to send notifications to users via email to remind the
user of pending voicemail message and sometimes attaches voicemail message as .wav files.
2.8 Conclusion
In this chapter, there was a review of the needs of VoWLAN in old peoples’ home and the
features VoIP will need to deliver in care home. The chapter critically analysed how VoIP
over WLAN (VoWLAN) offers an economical platform that provides mobility data and voice
access to busy, on-the-move carer staff, thereby providing Carers on-the-spot access to data
necessary for quality care of ward and work effectiveness. VoWLAN will also enable Carer to
have IP PBX features, giving carers the ease of IP phones that serve several purposes.
Furthermore, alternative means of communication in old people’s home were reviewed for
comparison. The chapters following in succession will further critically review how the
VoWLAN is achieved.
8
CHAPTER 3
REASSESSING VoIP over WLAN
3.0 Introduction
Businesses are moving over to VOIP because of the awareness of unified communication
which enables transporting voice, data and other multimedia functions across IP networks.
With VoIP, other services can be achievable like video conferencing, call text, call forwarding
and voice mail which make VoIP a multi-service communication solution (Sattar, Hussain &
Nisar, 2009). Apparently in today’s Telecommunication Market, service providers like Virgin
media, Sky and British Telecom make available VoIP services for many companies and
business enterprises in the United Kingdom. In employing VoIP service provider
infrastructural architecture, their client users may be forced to gain access to telephony
services through its Internet Service Provider. They are a few VoIP vendors that provide the
solution of offering Private Branch Exchange (PBX) server to enterprises and small home
businesses which are mainly software applications like the 3CX. This PBX software can then
be integrated into the Client networks to offer flexibility of adding old people’s home
desired features to fit distinctive specific purposes for their telephony system. This
integration of VoIP solutions is purely aimed at reducing cost for Care home and also giving
the enterprises the extra features to their telephony systems (Villacis, Acosta & Laracueva,
2013).
3.1 Concerns of VoIP on WLAN
It has been observed in literature that Wireless networks encounter some issues with
performance of transporting real time traffic (Sattar, Hussain & Nisar, 2009). Since VoIP is
real-time voice traffic, distinctive requirements are placed on the WLAN which is different
from requirements placed by data traffic on WLAN. These concerns of VoIP over WLAN are;
3.1.1 Quality of service and system capacity issues:
Quality of Service (QoS) is described a process of guarantying end to end delivery of voice
traffic in VoIP (Tebbani & Haddadou, 2008). This basically means that a receiver should be
able to recognise the Voice of a caller clearly with a good call quality during conversation.
Basically beliefs are that network resources are never enough, so therefore in VoIP, realtime voice traffic ought to have priority access in the network. However, when there is
enough or surplus available network resources for every kind of traffic, there may be less
need to prioritise traffic of any sort. Thus, the idea of QoS and system capacity is integrally
linked. When network system capacity is enough, there may be little or no need to deploy
QoS mechanisms. Hence, other known factors that influence QoS on Network system
capacity which are; packet sizes, transmission rate, Packetization overheads, distributed
control functions (DCF), point control function (PCF), overhead and In-built equality among
all nodes become irrelevant. According to (Khan & Ong, 2008), there are parameters that a
9
VoWLAN system should minimize from end to end in voice trafficking for the call quality to
attain the acceptable level for QoS. These factors are;
Packet loss: (Llays &Ahson) showed that Packet loss is when voice in form of packets is
forwarded to receiver by a sender but not properly received by the receiver as there
may be loss of content in voice packet, which usually results to discard of packet. Packet
loss occurs for a number of reasons: wireless link being overloaded facilitated by router
queue, receiver’s device being overloaded, disproportionate collisions on wireless link
and also low quality or interference, which typically causes physical media errors. Events
of packet loss cause degradation of voice quality (Schukat & Melvin, 2013). Audio
Codecs operation can facilitate packet loss by performing further refined interpolation
to phase out any interruption in an audio stream. A noteworthy fact by (Lee, Byeon &
Kim, 2013) points out that packet loss can become of greater concern once the
percentage of lost packet goes beyond a particular threshold which is 5% of the
transmitted packet.
Delay as (latency): (Davidso & et al, 2007) this is defined as the amount of average time
taken for voice packet to be transported to the intended end users from source in a VoIP
network. Voice packets delay is measured by the sum of all end-to-ends delay that the
functions of the VoIP system brings to the communications channel in-between the
signalling point and the reception point. Since VoIP is a sensitive real time application,
voice doesn’t need to put up with much delay. Delay of voice packet with a stretch of
100millisecond will compromise call quality (Sanyal, Bhunia & Mistra, 2011). In addition,
(Marquez-Barja, Calafate & Cano, 2011) considers latency as overall system time delay
amounted from Signal buffers, Signal filter, propagation delay initiated in the
communication path, processing of signals, digitization technique and Codec.
Jitter: In VoIP, jitter occurs when voice packets arrive at the reception node out of order,
leaving spaces in the framing arrangement of voice signal (Schukat & Melvin, 2013). It
can be defined as the variation in latency time from one voice packet to the next as it
reaches the end user. According to (Sanyal, Bhunia & Mistra, 2011), since voice packets
are produced at a constant rate from a voice source, once Voice packets exceed
tolerance of 75 milliseconds of jitter delay (preferred tolerance is 40milliseconds), the
voice quality will be compromised. Jitter buffer manages the effects of jitter in VoIP.
3.1.2 Security and Admission control:
802.11 network inherent complexities is already a security issue for VoIP on WLAN
(Woodhams & Smith, 2011). Therefore adequate security measures must be taken to
securely communicate over voice over WLAN. However, an improvement as seen in the
802.11i protocol fixes lots of loopholes observed in the 802.11 network (Sonntag, 2013).
Furthermore, admission control may be compromised when there are inadequate tools put
in place for access control to allow only authorized users while denying unauthorized users
10
access to the network. Hence, admission control is another core issue considered in
deploying VoIP over WLAN (Villacis, Acosta & Laracueva, 2013).
3.1.3 Roaming/ Hands-off Issues:
This is another critical issue with VoIP on WLAN. Since the VoWLAN operation is on a very
restrictive delay budget, the hands-off timing mechanism of 802.11r must not tolerate voice
delay less than a few 100 milliseconds for voice acceptability and better quality of service
(Chandra & Lide, 2007). Therefore, 802.11 handoff times are very crucial area in VoIP over
WLAN for our client’s organization.
3.2 Benefits of WLAN to Client Network
Device mobility.
Simple, flexible and scalable: devices can be easily added to the network without
extra wires.
Installation speed: less stressful to install a wireless network and smaller labour than
wired network.
Cost: less cost on labour to deploy WLAN.
3.3 REVIEW ON WIRELESS LOCAL AREA NETWORK (WLAN)
3.3.1 Overview of WLAN
All wireless local area network infrastructures need backbone networks which are wired
LAN infrastructures. Since the need of our clients is to implement VoIP on wireless LAN
because of roaming functionalities. Further discussed is WLAN components
3.3.2 WIRELESS STANDARDS
Table 3.1 showing Wireless standards adopted from Nortel.com
11
These standards represent radio frequencies and their characteristics. Wireless devices in
our client network must be capable of operating on two or more of these standards before
communication can occur in the network.
3.3.1A WIRELESS LAN TECHNOLOGIES
3.3.1B WLAN components: The components needed to form a WLAN for our client
organization are described below
Access Point (AP): This is a layer 2 device that connects to a wired network via
Ethernet port to produce wireless network to give access to mobile devices (Sung &
Lin, 2008). It operates via receiving from the wired network and sending out radio
frequency to wireless devices by translating Ethernet broadcasts unto radio
frequency so that wireless devices of care home workers connect to the network via
the AP and to the internet from the network (Brik, Mishra & Banerjee, 2008). This AP
can be deployed in our client ward rooms, carers and supervisors’ offices and
staircase to keep wireless connections. AP generates cells (Flaithearta, Melvin, &
Schukat, 2008). A cell is the transmission range of a wireless AP (Cisco) 2011.
Antennas of the AP form the cell. There are 2 types of access points which are critical
to the architecture of any WLAN and these are Lightweight access point (LWAP) and
Autonomous access point (choi, 2012).
Figure 3.1 showing Access Point: (Motorola) 2005
Wireless LAN Controller (WLC): According to (Radack & Kuhn, 2012), WLC is
employed to control and administer the AP and is crucial to the WLAN architecture.
WLC is employed to configure the Light weight access point which will be used to
give access to carers and supervisor in our client’s organization. (Robinson,
&Yedwab, 2013)This is because it gives authentication policy and supports security
mechanism with management of frequency band and selection of carrier channel,
and thus meets client’s needs as it helpful to managing several access points in an
12
old people’s home. WLC supports roaming client and it has a database that keeps
track of all the entries of devices, which stores the MAC address and IP address of
the device. It uses this information to track wireless client on the network. Other
features in MAC filtering supports 802.11a,b,g,n, security features of 802.1x,
Monitoring, Service Set identification, high availability, virtual LAN support, Powerover-Ethernet support and QoS support (Villacis, Acosta & Laracueva, 2013). The
WLC is the reason behind a centralized architecture.
Figure 3.2: Wireless LAN Controller. Source: (Cisco, 2011)
Lightweight Access Point Protocol (LWAPP) is the protocol that enables communication
between Wireless LAN controller and lightweight AP on the network by the LWAP using
the discovery mechanism and the Controller using the response mechanism. Cisco, 2009)
relates that the Control and Provisioning of Wireless Access Points (CAPWAP) is an
interoperable protocol which makes a WLAN Controller (WLC) to manage APs.
Wired Network or distributed System (DS): The physical medium consists of router,
switches, WLC, mobile IP phones and internet service provider (Villacis, Acosta &
Laracueva, 2013).
Network Interface card. Mobile devices possess network interface card to associate
with the WLAN.
3.4 WIRELESS LAN TOPOLOGIES
A Set Service specifies how radio communication goes on with respect to devices that make
WLAN. Technology that concerns the scope for project for Clients organization is the Basic
Set Service and the Extended Set Service
Basic Set Service (BSS): The networking component that is needed to form a BSS is
one access point with nothing less than 1 mobile device. In a BSS, the
communication that takes place between devices must pass through the access
point; therefore, all devices require an association with the access point (Frohn,
Gubner & Lindemann, 2011).
13
Figure 3.3: The Basic Set Service. Adopted from TX.COM google (2006)
Extended set service (ESS): An ESS consists of 2 or several more BSS that is linked
through a distributed system. A set of different AP and associated end user devices
remain connected through a distributed system and this forms an ESS (Villacis,
Acosta & Laracueva, 2013). Carers and supervisor mobile devices in our client’s
organization are handled by an AP in one cell; however, client can move to another
coverage area handled by another access point and still stay connected to the
network for calls and data transfers. Therefore handover/roaming is attained where
there is an overlap between Access Point cell areas (Radack & Kuhn, 2012).
14
Figure 3.4: The Extended Set Service. Adopted from Google Nortel (2002)
Service Set Identifier (SSID): SSID is the name WLANs displays given by an
administrator of the network. Mobile devices access WLAN by identifying with the
SSID, which an AP broadcast within the cell. The frames that publicize the SSID are
referred to as beacon (Cai, 2006).
3.5 Recommendation
The use of WLC makes it easier to deploy more access points which will be centrally
managed.
3.6 VOIP ARCHITECTURE
In line with (Baharlooei & Hashemi, 2009), it explains that basically a VoIP system should
comprise of end points typically telephones, softphones, control and access nodes and
gateway nodes together with an IP network, and on many occasion a PBX. Each component
has its functionality in the VoIP setup as where the softphones and telephones can be used
to communicate over the VoIP network when calls are setup. Components functions are
explained below:
Gateway node: Gateway nodes are setup for calls going out of the enterprise VoIP
system to PSTN and other public network (Korchi & et al, 2008).
End-points: Endpoints are the interfaces via which communication between users
takes place. They come in either hardware of software, for example IP phones or
Zoiper application. According to (Khan & et al, 2012), an end point is a terminal that
can connect to the IP network because of its capabilities.
IP network: The interconnectivity between several nodes forms a network, and is
formed basically for resource sharing. The IP/TCP protocol interconnects nodes
together over a VoIP network (Sfairopoulou & et al, 2011).
VoIP Server: This is the heart of a VoIP network, where the administration activity of
the network goes on (Chava & Ilow, 2007). VoIP server must grant access to any
activity in the VoIP network before it can carry on. It carries out functions of
translating codecs, routing calls and features needed in our client’s organization like
auto-attendant and the interactive Voice Response features.
3.7 THE 3CX VoIP Server
3CX is now becoming a popular IP-PBX software solution, the 3CX telephone system is going
to be deployed in our client’s network because of ease of implementation and the extra
features it brings. The 3CX is a SIP supported PBX software used also on windows to provide
support to SIP phones. 3CX IP PBX is interoperable with other VoIP equipment. In addition
3CX offers the remote site flexibility by allowing workers work from home.
15
In line with (Butcher, 2007), the centralized and decentralized architecture are the 2 basic
architectures in VoIP. The centralized architecture is particular to our client network and is
discussed below. A VoIP provider is need to connect calls to other network such GSM and
PSTN
Centralized Architecture: The centralized VoIP architecture can also be referred to
as the Hybrid-IP architecture which uses a central call processing/ switching server,
whereby communications from client’s staff phones are mediated by the VoIP
central server which is the PBX. According to (Chava & Ilow, 2007), the VoIP call
server will switch calls within the client’s network. For our client’s network the call
server will have the authorization to put end users to company policies with respect
to VoIP phone system. The centralized architecture is chosen because of the rich
functionalities a PBX offers and ability to setup call in a short time, though it
disadvantages come as issues with single point of the failure, scalability issues and
unbalanced load. However, backup PBX server can be implemented in a VoIP
network so in the event that a call server fails, the redundant PBX can take over
responsibility (Alidoosti & et al, 2013)
Recommendation
For Client’s VoIP network system, the VoIP Call server or PBX will be used to process
and control calls within our client old people’s home which makes it a centralized
system.
3.8 Codecs
Codecs will enable our Client’s Workers Voices on a call to be converted from analogue
signal to a digital signal and also compress voice too. The G.711 a-law, G.711 u-law and
G.722 are compatible with 3CX and is a potential to be used in our Sponsor’s VoIP network
system. Though, earlier literature did not do much on the best codec to deploy.
16
Figure 3.5: Centralized VoIP Architecture. Adopted from (Chava & Ilow, 2007)
3.9 VOIP PROTOCOLS
VoIP communication is usually of 2 phases;
call control and signalling phase
transporting and carrying of voice payload
These phases are both dependent on protocols for effective communication in any VoIP
system.
3.10 Signalling Protocols That Can Be Deployed on Client VoIP Server:
protocols which such as Session Initiation Protocols (SIP) and H.323 are accountable for
signalling, recording and facilitating main events in a call; which is initiating the call,
modifying the call and tear down of the call when end users are making attempts to use
features on their telephone system like call transfers and call conferencing (Jang & lee,
2007). However, it is imperative to bear in mind that functions of signalling are on a
completely set aside packet stream from the real voice bearer path. H.323 and SIP are the
contending signalling protocol.
H.323 is signalling protocol suite that uses H.323 Gatekeeper to provide translation
between IP addresses and telephone numbers and also offers call control, call
monitoring and call registering (Briones & et al, 2013).
Session Initiation Protocol (SIP): is specific to our client because 3cx deploys sip as it
signalling protocol, and most of all it enable calls within workers in sponsor’s
17
organization. SIP is a signalling protocol, located on the application layer, an RFC
3261 standard proposed by the Internet Engineering Task Force (IETF). SIP signalling
character will enable call in our client network and allows multimedia sessions at
every given phase for the initiating, modifying, and terminating of both voice and
multimedia sessions (Alshakhsi & Hasbullah, 2012). According to (Roebuck, 2011),
the author suggests that SIP can also support other feasible application like online
gaming and distribution of multimedia streams. However, (Kaza & Asadullah, 2006)
pointed out that SIP is a peer to peer protocol, making SIP assume networking
capabilities of routing calls, managing call and multimedia sessions distributed to all
nodes (call servers and client end points) in the SIP VoIP network. SIP operates as it
allows a protocol named Session Description Protocol (SDP) to allot the features in
the media session layer for call and multimedia establishment (Alison & Ilyas, 2009).
SIP provides the selection of addressing arrangement and is intended for a central
topology. SIP interacts with Transport protocols in Transport Control Protocol (TCP)
and User Datagram Protocol (UDP) for transporting of voice mainly the UDP (Sung &
Lin, 2008).
3.11 Recommendation
With all this characteristics of signalling protocols, SIP is the preferred signalling Protocol for
our Client’s VoIP system.
3.13 MEDIA PROTOCOLS
In VoIP, both User Datagram Protocol (UDP) and transmission control protocol (TCP) are
operable by SIP (Briones & et al, 2013). TCP is employed for reliable transmission of data as
it gives a user error feedback when there is packet loss and retransmits data again.
However, TCP characteristics are not suitable for real-time application like VoIP, because
extra time and excessive bandwidth will be drawn to resend voice packet that were lost
during several transmissions. Though UDP is an unreliable protocol, however it is suitable
for real-time application like VoIP as it does not retransmit packets after it has been sent the
initially (Lee & et al, 2013).
SIP employs Real-time Transfer Protocol (RTP) to deliver audio (Voice) call in our client’s
VoIP network. In a VoIP context, RTP is used for end-to-end, transfer of real-time audio
(voice) stream (Roebuck, 2011). According to (Flaithearta & Melvin, 2013) RTP functions by
making available facilities for detection and compensation of jitter where data arrive out of
sequence, typically on an IP based network. RTP support identification of different kind of
payloads, real-time voice packet timestamps and also monitors the way voice traffic is being
delivered (Briones & et al, 2013).
18
(Cisco, 2011) further describes the RTP combination with the RTP control protocol (RTCP)
which is a protocol that functions by monitoring the voice transmissions statistics and QoS
to support multiple voice stream synchronization.
3.14 VOIP SECURITY
The most common security for the VoIP is the
Secure Real-time Transmission Protocol: In line with (Butcher & et al), the SRTP is a
protocol on the transport layer that secures real-time application such as voice, by
encrypting real-time voice packet to prevent the audio stream of our client devices
from attacks.
3.15 The Integration of VoIP to WLAN
The first step to integration is that all mobile devices with a WLAN interface that want to
associate with the WLAN must be IEEE 802.11 capable; devices must be capable of searching
for wireless LAN SSID with the help of wireless LAN adapter. The device obtains an IP
address as soon as it gets access to the WLAN, then registers to the VoIP PBX server by
taking the IP address of the PBX then uses it as the gateway of the VoIP softphone
application, then the device can begin to communicate since SIP is present, calls can be
setup. (Cisco, 2011) recommends that industry best practice connects the VoIP server to the
wired network.
3.16 Roaming/Handover
Roaming will describe our client’s workers movement with their mobile devices,
disconnecting from one access point (Cell) and connecting to another access point in an
(ESS) within the care home premises and retain connectivity, which by good practices there
must be an overlap of channels between the 2 APs. Overlap is when cells lap over each
other. Overlap occurs at 15% between cells before roaming can work efficiently (Evans,
2012).
19
Figure 3.6 Wireless communication module, COMM3E (Evans, 2012)
Figure 3.7 SHOWING ROAMING. Adopted from APTECH Engineering.org (2010)
In the above diagram, the circled areas are referred to the cell. For client’s network,
roaming voice traffic will make up the network design. (Cisco, 2012) has labelled the 802.11r
as an 802.11 extension to enhance and solve roaming issues, while radio management is
taken care of by the 802.1K. Our client’s WLAN network will consider the roaming Voice
traffic before any other traffic, and the below type of roaming is considered for client’s
network
20
Intra- extended service set roaming: This is the type of roaming between APs joined
by the same WLC and in same extended-set-service where the network SSID, VLAN,
security deployment, and IP Subnet are the same, this is done without disconnecting
our client’s workers devices. (Huang, et al., 2007). The WLC gives update of users
database as the new association to new AP occurs and IP address remains
unchanged
FIG 3.8 Adopted from Cisco, 2010, roaming between access point. REF CISCO.COM
Intra-extended Service Set roaming/subnet change: This is the type of roaming our
client’s workers devices could experience when moving between APs in the same
(ESS) where IP subnet of devices are liable to change during mobility (Kim, et al.,
2012)
LAYER 2 intra Controller roaming: In this kind of roaming where our client’s devices
can roam from AP to AP joined by different WLC but are on the same subnet and end
user devices IP address remain the same. This happens when end users traffic are
bridged to the same IP Subnet.
21
FIG3.9 Showing INTER access point Adopted from Cisco.sunderland.ac.uk.
layer 3 roaming and mobile IP: Layer 3 roaming takes place when mobile devices
move from one AP belonging to one subnet and a WLC and associates another AP
that belongs to a another subnet on a different WLC and still maintain the same IP
address(David) 2012. The Way out is to create tunnel. Asymmetric Tunnelling – end
users traffic after it has moved to its new WLC domain are routed to the destination,
Returning traffic is then forwarded to the end users Old WLC then tunnelled to end
users new location .
Perhaps, this level of roaming may have been recommended if our client’s network
was much bigger, where they are multiple floors in the building. This is adequate for
bigger enterprise network.
3.17 According to (Cisco, 2011), the 802.11r gives the basic support for roaming
Mobile devices connect to/associate with the strongest AP in the Basic Service set.
Mobile devices stay associated to the AP till it’s disconnected.
When disconnected, mobile devices scan all the channels to look for the AP with
strongest signal available.
Mobile devices authenticate and associate with new access point.
22
3.18 KEY TERMS OF ROAMING PHASES
3.18.1 Scanning: In this phase mobile devices discover available accessible access point as it
observes beacon frames that are broadcasted in periodical session by Access points (Kim, et
al., 2012). Scanning types by mobile nodes are;
passive scanning is when mobile device wait for beacons from APs
Active scanning is when mobile devices solicit for beacons
Synchronous scanning is when mobile devices depend on the access points timing
Asynchronous scanning is when mobile devices make use of the info saved on the
access points site table to know when radio turns on to so it can accept beacon from
the preferred access point
Broadcast scanning is when mobile devices send probe request with broadcast
address.
Unicast scanning is when mobile devices send probe request to a particular AP, if
through the site table it has connected the AP in a session.
Typically Access points operate in 1 of numerous channels (e.g., 11 and 14 channels in
802.11b/g/n) and thus a scanning device tries to discover Access points in every channel
(Fliathearta, Melvin & Schukat, 2013).
Fig 3.10 SITE TABLE Adopted from Secure Roaming by (Goransson &
Greenlaw, 2007)
23
3.18.2 Authentication: 802.11 networks access can be restrictive by employing security
mechanisms. In WLANs mobile devices are compelled to interchange authentication
messages with the identified access point for association (Villacis, Acosta & Laracueva,
2013).
3.18.3 Association: In this phase the mobile device associate the new access point by
forwarding association request and gets an associate identity. As explained by (Jerjees & AlRaweshidy, 2011),in a case where the Inter Access Point Protocol is deployed, the newly
found access point informs the previous AP the mobile node association is changed, and
thus cannot communicate with mobile devices.
3.19 Client’s premises
Client’s care home apparently is a bungalow building, and has a basement staircase for an
underground office. The client’s has 7 rooms’ for wards and can take 10 ward bedded space
per room. The staffs of care home have four offices in total and take 7 persons per room,
with a reception helpdesk. Room and office dimension for client’s premises are at;
18m x19m for the ward rooms
16 x 16m for offices of staffs
3.20 Client’s Present network
The client’s care home has a central reception PSTN telephone with 12 extensions in
Different rooms in the building. The building has 3 deployed autonomous AP at 20 metres
which 1 is situated in the reception and the remaining 2 in supervisors’ room for data use.
The building also has a small server room with a router and 1 switch and AP to connect a
few systems in the building
3.21 Client’s VoWLAN needs
Our client needs a solution to enable carers in his care home to multitask on their job via
quality voice calls as they could be caring for two or more wards within short intervals in
different location of the care home facility which involves being mobile. In order to meet
these needs as discussed earlier in chapter 2, as (Taylor & Wilson, 2009) justifies that calls
made over WLAN are cheaper than calls that made on PSTN phones and also provides
mobility and fulfilling unique needs in care home.
3.22 Client’s Telephone system and Network issues
The PSTN lines are not cheaper option as compared to VoIP (Irving, 2012), so therefore
consideration for VoIP is paramount. However, the Issue with our client network is that it is
disjointed. The wired network in client’s building does not cover the whole areas needed for
24
voice likewise the Wireless LAN. The deployed 3 autonomous APs are widely dispersed from
each other with no overlap in RF area of the building and are used for sending emails and
files. Hence, there will be a potential drop in call perhaps if a VoIP server was installed and a
wireless IP phone moved from an AP during a call session.
3.24 Recommended solution
As the client requires mobility voice which requires a continuous RF coverage (Fitzpatrick,
2011). Light weight access points (LWAP) will be deployed at every 7metre with an overlap
on each cell within the care home facility. The access points will be controlled by the WLC as
stated earlier in this chapter, which connects the router and the switch. (Cisco 2009),
recommends that the switch provide the connection for the VoIP sever and the access
points. The wired network devices like table IP Phone can interact with the wireless IP
phones on the wireless lan. Thus, this solution will support roaming round the care home
facility for the wireless IP phone to move with carers on a call.
FIG 3.11 Overlap of cells with channel non-overlap, Adopted from CISCO, 2009 FROM
CISCO.COM
3.25 MOBILITY DECISIONS: During mobility of mobile devices there may be different
decision for handoff handover criteria. These decisions are;
When to roam
Where to handover
How to roam
When to Roam: As accentuated by (Lee, et al., 2012) the handoff practice in WLAN is first
initiated when there is a signal-to-noise ratio or drop in signal strength on mobile devices in
25
it associated AP and the mobile device needs to associate with another cell. It occurs where
there is detection of cell search threshold by mobile device (Huang, et al., 2007). When to
roam is implemented by some key practices when the disconnection to current AP:
Access point clearly directs a Disassociation messages to mobile device
Mobile devices fail to get threshold sum of beacons from access point
Mobile devices fail to transmit a threshold of packets to the network/AP
Mobile devices notices its or the Access point rate-adaptation algorithm lodging
in on the lesser rates (Huang, et al., 2007).
Security handshake/re-key failures.
It is a necessary approach not to hold back mobile to be disassociated from present AP
before beginning the actual handover. In line with (Villacis, Acosta & Laracueva, 2013), the
Received Signal Strength Indicator (RSSI) assigned to network devices is an index for signal
strength and indicates power level received by antenna of mobile devices, used to decide
intra-ESS handover. RSSI is used witness fluctuation due to fade of signals, intervening
objects and multipath and anticipate a move for handover. RSSI decides when the mobile
needs to roam from an AP as it indicates weakness in signal strength.
1. Where to handover: As explained by (Chandra & Lide, 2007), this is to determine by the
mobile device, the next AP to associate with. With a scan algorithm, mobile devices will
gain access to updated site table, and this decides the AP to associate. The site table
shows all the APs signal quality and compares the quality of current AP with the quality
of other aspiring AP (Boulmalf & lakas, 2006). As described above the RSSI measures the
signal strengths of APs in an ESS. Every single entry in the Site Table has a correlative
RSSI and a rudimentary roaming/handover algorithm compares RSSI of accessible
available access points on the Site Table to agree on where to roam to (Chandra & Lide,
2007).
2. How to roam: Describes the processes of disassociating from an Access point to
association to another access point. At this point, mobile devices sends broadcast probe
request message to all channels of the access point (Briones, Coronel & Chavez-Burbano,
2013). Probe messages have the SSID details of network to which mobile devices wish to
connect to. Access points that receive probe requests messages may well give reply with
probe responses message, declaring their cell open and if the mobile devices want
connect with its own network. Then, when the probe response message is received,
mobile device begins authentication processes (Chandra & Lide, 2007). The purpose of
the process of authentication is to reliably form an identity with communicating mobile
device.
The next phase is the association phase; the purpose of association procedures is to
form a connection logically between AP and mobile devices. Association first begins
when mobile devices sends the request for association to the AP. This request holds the
parameters like the information of capabilities and rate the mobile devices can be able
26
to support (Kashihara, Horiachi & Nsiwar, 2009). The access point replies with the
Association Response message, which could reject or accept the association which is
dependent on parameters that put up in the Association Request message. After a
mobile device is associated with the AP, the network now knows and identifies “the
location” of this mobile device in the cell and sends voice or data traffic to the
destination of mobile device (Chandra & Lide, 2007).
3.26 VOICE AND ROAMING
VoIP uses the UDP to Transport voice which is an undependable protocol during roaming.
VoIP which is a Delay sensitive application, as (Sfairopoulou, Bellalta & Maci´an( 2008)
stated that end –to end voice budget is 250ms and should not exceed that limit; with the
whole total delay end-to-end. When mobile device of carers in our clients care are on call
session and moves from an AP, as it begins to move from current AP, the mobile device
starts to lose signal strength and thus it start to go into the discovery phase where it starts
to scan for available AP. During the discovery phase and scanning, the reduction of signals
strength makes the call start to degrade voice quality. After discovering APs, this is the
phase of sending and receiving probe request message between carers mobile device and
available APs which then accounts for 90% of handoff/handover. According to (Fliathearta,
Melvin & Schukat, 2013), further degradation to voice will occur because of roaming causes
more delay. The next phase is the Re-authentication phase, where mobile have to
authenticate and re-associate to new AP, voice call quality will suffer further degradation
due to authentication delays. However, (Lee, et al., 2012) points out that with all the
different delay associated with the 802.11 networks on voice, a decent VoWLAN
deployment should target limiting 802.11 delays to 40–50ms. During roaming mobile device
IP address a times changes, an IP address switch can further affect delay (handshake delay)
and call re-initialization and signalling (Session initiation protocol registration).
For roaming to be managed the RF may be altered to reduce coverage area. This WLC radio resource
management module can be used to reduce access point range and wireless devices will have to
choose the stronger signal in most case during mobility.
3.27 QUALITY OF SERVICE SPECIFIC FOR (VoWLAN)
As discussed earlier in this chapter QoS functions by giving preference to a certain type of
traffic class over other class of traffic (Flaithearta & Melvin, 2013). QoS means the ability of
the network to offer a better or special service to a group of end users or applications to the
detriment of other users or applications (Cisco, 2011).
The client’s network may carry out QoS model such as;
27
3.27.1 Best Effort Network Model: Is a QoS model where all devices needed to form a
VoWLAN is deployed and voice traffic is sent from source to a destination with expectancy
of voice packet to get to destination unaltered or lost or delayed, voice packet are
forwarded short of guarantee of throughput or reliability (Sung & Lin, 2008). In this model
no priority traffic in this model, traffic is goes with first to come first to serve base.
3.28 QOS DEPLOYMENT FOR CLIENT’S VoIP NETWORK
3.28.1 Integrated Service Model: In this model (RSVP) Resource Reservation Protocol is
enabled on router to internetwork end-to-end connection between caller and receiver (Bint
& Yusoff, 2008). As soon as call initiation occurs, the RSVP requests, obtains and reserves
bandwidth of network during the call session. RSVP messages carries information of QoS
between ends of caller and end point of receiver. RSVP aid to determine best path in
channels to traffic voice from source to destination with help of basic protocols. The
integrated service model guarantees voice traffic to destination but is not scalable with
larger networks.
3.28.2 Differentiated Services Model: In this model the interworking devices are configured
to QoS policies by the admin of VoIP network to function individually (Cisco, 2011). No
bandwidth reservation is needed in this model. QoS instructions are identified on the voice
packet headers. It’s scalable in both large and smaller VoIP network. During movement of
packets in the network, switches or router try to compare the classified (or marked) to
define the process of forwarding. Classification is typically carried in the headers of IP
packets employing six bits IP (TOS) type of class field.
LAYER2 QoS
During transmission of frames between layer 2 devices (switches), these frames being
transmitted can be classified. However, information of the Virtual Lan is to be transmitted
between the switches trunk link that are employed. As the trunk links enable the
encapsulation of frames together with the field that indicates the VLAN identity. (Bint &
Yusoff, 2008) demonstrates that the encapsulations includes the field that marks the CoS
class of service for every frame. Layer 2 CoS values range from 0 for low priority to 7 for high
priority (ciso, 2011)
Layer 3 QOS
IP packets require (TOS) Traffic or Service byte employed for marking packets. Byte uses the
IP precedence of 3-bits to define the per-hop packets behaviour. The 3-bits Bytes are
referred to as Differentiated services while the 6bit are called the Differentiated Service
Code Point (DSCP). (Cisco, 2011) showed that the following characters supports DSCP values
0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48 and 56.
28
FIG 3.12 QoS classification (Cisco, 2008) SHOWING LAYER2 AND LAYER3 CLASSIFICATION
(PACKETS AND FRAMES)
3.29 QoS MODEL INBOUND OPERATION
1. Classification: means to identify traffic and categorize it the traffic into classes
2. Policing: This Point, the model for QoS employs policies configured to decide whether
packet goes into or out of profile. The outcome of policy processes is sent to marker.
3. Marker: The marker decides the suitable operations to be used on voice packet into or
out of profile dependent on policy practise and the information configured. Likely operation
comprises of traverse and mark down of voice packets.
Figure 3.13: Configuring QoS TABLE: (Cisco, 2011)Queuing operation carried at (inbound
and outbound)
29
4 Queuing: Queuing is a method in QoS employed to evaluate QoS label and the conforming
differentiated Service Code Point or Class of Service (COS) value assessment to choose
which of the 2 inbound queues to place a voice packet (Cisco, 2011). Selection of any of the
4 egress queues is made after the evaluation of QoS Label and correspondent CoS and DSCP
value (Cisco, 2011).
3.29 Queuing Mechanism
There are several Queuing methods but since we are concerned with Queuing method that
will support client’s VoIP network, we will be focusing on Priority queuing and Low latency
queuing.
Priority Queueing: According to (Hasbullah & Alshakhsi, 2013), it states that more
than a few queues of pre-configured sizes are formed where packets are being
emptied specified by the access list on the basis of a stringent priorities. For our
client’s need, voice packets will be given a higher amount of priority than data
packets in the organization’s network, where the greater priority packets will be
emptied beforehand then the less priority packet can follow. This type of queuing
can be employed to guaranty voice packet in client’s VoIP network when voice is
given higher priority. Though, the demerits of this queuing method is that when
most of the packets transmitted across the network is a high priority packet, the
lower priority packets hardly get through when network bandwidth resources is
limited (Kim, et al., 2012).
Low latency Queuing (LLQ): This employs stringent priority like the priority queuing,
however the bandwidth is limited. All the other traffic categories will be classified in
a manual order and will be offered minimum guarantee of bandwidth to have a fair
share (Chandra & Lide, 2007). It is the recommended queuing model for VoIP which
is in line with the view of (Hasbullah & Alshakhsi, 2013).
3.30 QoS ON WLAN
802.11e/802.11p is QoS for WLAN. Voice traffic should have higher traffic priority than
other traffic for client needs. As explained by (Cisco, 2011), 802.11e is the definition of the
enhanced medium access mechanism specified to support QoS requirement. HCF (hybrid
coordination function) offers 2 access methods that give QoS supports. These access
methods are the HCF Control Access (HCCA) and Enhanced Distributed channel Access
(EDCA) Protocol which is an enhanced and modified version of the Enhanced Distributed
coordination Function (EDCF) obtained from heritage DCF protocol for 802.11 (Chandra &
Lide, 2007). WLAN 802.11 make use of the Distributed Coordination Function (DCF) for
collisions avoidance using RF carrier sense, inter-frame spacing, and arbitrary wait timers to
avoid collision. The EDCA offers priority dependence on upper layer protocols. The aim of
30
the QoS 802.11e/WMM Wifi Multimedia mechanism gives priority capabilities to WLAN to
enhance end user experience and optimize the performance of a desired traffic at the
expense of contending traffic. In our client’s VoWLAN network will be designed to give voice
higher priority over other traffic in our (Khan, et al., 2012)
WLAN traffic is tunnelled between the AP and the WLC through (LWAPP). To sustain original
QoS classification over this tunnel, QoS sets of already encapsulated data packets have to be
properly mapped to Layer 2 (802.1p) and Layer 3 (IP DSCP) fields of the outer tunnel packets
(Cisco, 2011). QoS provision on the WLC provides the WLC the abilities to relate the same
priorities that are set on the wired network (or the VoIP 3CX application) as it does not
perform QoS only itself but also recommends the Layer3 LWAPP in order for deploy CoS
QoS. (Chandra & Lide, 2007) showed that the WMM/EDCA deploy the 4 end user access
categories or priority levels. This priority levels profiles are determined by the back-off
counter and inter-framing mechanism which is time interval constrained.
The 4 Access categories are:
Priority lever 1: voice traffic
priority level 2: video traffic
priority level 3: best effort traffic
priority level 4: background traffic
FIG3:14 showing WMM Queues
For each priority access level, access category1 have the shortest interval, which will enable
voice go through faster on a traffic queue (Hasbullah & Alshakhsi, 2013). Access points
make use of QoS profile that is concern with end users priority to obtain DSCP value that is
employed on the Wired LAN.
31
FIG3:15 showing timE waiting interval WMM Queues
32
Chapter 4
Prototype Design chapter
4.1 Introduction
Chapter 3 discussed areas of roaming critically, QoS mobility support, VoIP and WLAN
architecture which is critical to this chapter and recommendation made will be the
reference in designing our client’s VoIP network. This chapter is to discuss
4.2 Client Requirement
Our Client has indicated that the VoIP network should be less expensive and also possess
mobility capabilities. However, it should be easy to use and capable of possessing clear call
quality while roaming. The client also requires full functionality of VoIP rich features that will
be specific to his organization mention in chapter 2.
4.3 Network Design approach
The Cisco certified design associated self-study and certified guide by (Hutton, k., Ranjbar,
A., 2006) and (Bruno, A., Jordan, S., 2011) recommends the top-down approach for critical
network design procedure. The top-down approach will stem from showing each technology
and device deployed in network design on the OSI model
OSI MODEL
Recommended design and devices
APPLICATION
3CX IP PBX
PRESENTATION
VOICE CODEC (G.711, G.722 AND G.729)
SESSION
SIP
TRANSPORT
RTP, RTCP, UDP
NETWORK
IP, QOS SUPPORT. ROUTER, WIRELESS LAN
CONTROLLER
802.11 b,g,a,n, 802.11r AND 802.11e, VLAN,
ACCESS POINT, LAYER 2 SWITCHES, WLC
HUBS,
DATA LINK
Physical
TABLE 4.1 DESIGN TABLE
Router: It issues IP addresses to hosts in the network through Dynamic Configuration
Protocol (DHCP). The Router is responsible for routing packets across the network and also
implementing VLAN deployment on of sub-interface router.
Switches: used in creating virtual segment in network by deploying VLAN
4.4 Network Structure Design (Logical structure)
Virtual local Area Networks (VLAN) is used to separate subnets on a switch in a network,
such that they physically they are in the same subnet but virtually on a different subnet and
vice-versa.
33
The unique VLANs per switch is critical to our design as more than 1 VLAN exists per
switch (Hutton, k., Ranjbar, A.,) 2006. Industry best practice prefers unique VLAN
per switch which is important for optimization in our client network other than the
One VLAN per switch where only one VLAN exists on a switch. For design of our
client’s logical network structure, the VLANS are created to separate the Wireless
LAN and Wired LAN on the switch. Where a VLAN is created for the group of
working staffs in client network to either be on wired or wireless Local Area
Network. On the other hand, interface VLANS are deployed on the router to carry
DHCP pool traffic for the WLC. However, VLANs security still exits as the ports on the
switch are assigned an identity which is WLAN AND WIRED LAN.
Interface VLANs
The VLANs interface created on the router will associated with a physical interface on the
router and this physical interface will serve as a trunk port to transport traffic for the
created VLANs for the WLC.
4.5 WLAN Network Design
From the recommendation in our previous chapter the centralized WLAN architecture was
chosen, and the centralized VoIP was recommended because of the use of an IP PBX which
is 3CX. A WLAN is characterized by LWAP, WLC, Routers and Switches. As discussed in
chapter3 the RSSI enables Access points and mobiles devices for measuring capabilities and
rating signal strength.
(Bruno, A., Jordan, S., 2011) points out the Hierarchy network design model, which are the
Core layer: is regarded as the backbone of the network for high switching and is
critical for connectivity and availability
Distribution layer: is the point of isolation with layer 2 and layer3 switching function
and implements policies needed for the access layer.
Access layer: this layer gives access to users of network.
The client’s organisation is a single site, so our design does not cater for remote
deployment. The design for WLAN network allows the WLC to enable the access point
perform lntra-controller roaming. The APs allows mobile devices authenticate to the
network all which are been managed by the WLC. Hence the access points in client network
are on the Access layer. The layer2 Switch bridges the gap in the network to link the LWAP
to the WLC and the wired network to router with the VLAN creation which is access layer.
The router switch in the network influences the routing activities, which from a hierarchical
network designed model perspective it is on the distribution layer (cisco) 2012. The WLC is
in distribution layer as gives of mobility and QoS, security, and AP management.
34
Using of 2 WLC will serve for load balancing and redundancy. However the Scope of this
project doesn’t cover this area.
Service port: this employed to cater for out-of-band management (cisco, 2011); this will
include opening setup for the WLC
Management interface: it is employed by the LWAP to enable association with the WLC.
There is only 1 management interface for the WLC for this design. IP address is-
AP manager interface: AP manager is employed to enable all LWAPP traffic between the
LWAP and the WLC. The AP manager interface is-.
Virtual interface: The Virtual interface according (cisco, 2011) is a Unique IP address per
mobility group that enables communication between the AP and WLC for Web
authentication, mobility, IP Security (IPSec) and DHCP relay.
4.6 The Telephone 3cx server
The VoIP server is deployed for processing the voice traffic in the network. The VoIP server
connects the network by connecting to the switch and it’s manually assigned an address
from the wired network. Deploying the VoIP server on the wireless LAN is not reliable,
because when there is loss of signal in the WLAN, then the application the server is servicing
suffers availability issues.
The IP Address of the VoIP server will be used as the gateway for SIP client in order to
communicate on the VoIP network. The VoIP server IP address will be-, gateway
address-. The UDP protocol is used to transfer the voice packet between carers
in client organization.
4.7 Design for Roaming.
(Cisco, 2011) recommends that WLC group must have the same IP address for the virtual
interface, for instance 1.1.1.1. This is significant for roaming and its best practices.
Since the roaming in our client’s network will be the roaming within access point where IP
address remain the same for wireless devices. The network will be designed at the Intracontroller roaming level. The inter Access Point Protocol (IAPP) will enable our client
workers devices roam within access point in the care home facility by using inherent
characters in the announce protocol and handover protocol. The 802.11k protocol will be
used to adjust parameters on the Radio Resource Management for APs, and to manage
radio frequency level for access points for overlap in laboratory. The Cisco central Key
Management protocol is used to secure quick roaming to reduce handover delay time in the
client’s network design.
(Cisco, 2011) recommends VoIP over WLAN success to the following criteria
35
Definition: defining the priority Traffic and who the traffic is intended for the Old
people’s home
Coverage: For APs with MIMO high gain antenna will be mounted on wall vertically
Cell distribution: AP cell size reduction should be implemented to reduce client
number in a particular cell to avoid insufficient bandwidth. This is deployment is
critical to client’s network.
Radio frequency (RF) Environment: RF Auditing is to check building structure and RF
Cell coverage and devices to be used. RF audit still Checks for other non-Wi-Fi
devices such as microwave and Bluetooth to know the amount of RF power to be
transmitted (Cisco) 2011. RF Test and adjustment is to examine the deployed RF and
Adjust accordingly.
Channel Selection and utilization: Overlapping cell will make use of non-overlapping
channel. (Cisco) 2011 further explains that if the same channels are required in
multiple cells, it is not necessary to overlap cells. So therefore overlapping cells
should avoid using the same channel to avoid co-channel interference. Using cisco
recommended cell size for voice the AP cells will be at -67DBm, however alteration
to attain voice quality may be done.
Further recommendation from cisco is to make use of 802.11a 5 GHz Wi-Fi band as
recommendation for deploying VoWLAN, However devices in the laboratory are
mainly 802.11b/g and n (2.4GHz) capable. So therefore enabling 802.11a, b and g on
the access point is designed. Utilization of channel will be under 50%
cell overlap between access point is 15-20% if the
Signal to noise ratio at 25dB For more for effective coverage
#
36
FIG 4.1 SHOWING WLAN AP deployment Cisco, 2011.
CORE LAYER
ISP/ VoIP provider
DISTRIBUTION LAYER
AP management
management
Wireless lan
controlle
r
Wireless Lan
controller
Distribution layer
Switch1
ACCESS LAYER
ACCESS LAYER
Switch2
Radius server
Access point
PBX
Voip server
Carer2 mobile
Phones
Access point
Wired network
FIG 4.2 Recommended Design for clients Network (self-designed)
The design above is an economical and reliable design for our client’s network. However,
the focus is putting up a design to support call mobility. The below design is self-designed
and is done to facilitate the building of the prototype network in the laboratory but delivers
the concept necessary to effectively carry out voice roaming in my client’s organization.
37
DISTRIBUTIVE LAYER
DISTRIBUTION
LAYER
Wireless lan
controlle
r
management-
AP MANAGER INTERFACE-
Router
192.1.1.2
Switch1
ACCESS LAYER
IP add-
D.G-
Access point
Phones
PBX
Access layer
RADIUS SERVER-
VOIP SERVER-
FIG 4.3 PROTOTYPE Network for laboratory practical (self-designed)
4. 8 Justification for Network design
This design is a very economical design as it’s a single site deployment. Segmentation of
the switch and assigning of ports through creating VLAN is evident to this design. The
reason for the multilayer switch rather than a router is that it can function as a switch
and also perform routing functions. The layer3 switches are faster devices also. The
RADIUS server is used to secure the wireless client in the network and has a shared
secret with the WLC.
4.9 Proof of design Concept
IP Addressing
The Class C address will be adopted because of little number of staffs, and our client’s
organization is not big enough financially to acquire bigger address block.
Address Scheme:
38
DHCP SCHEME
IP DHCP POOL
NETWORK
Management
-
DEFAULT
ROUTER-
Malonecarevoice
-..0
-
Malonedatacare
-
-
TABLE 4.2 DHCP SCHEME
INTERFACE
VOIP SERVER (VLan )7
Radius Server (Vlan) 7
Wired interface
TABLE 4.3 SERVERS
IP ADDRESS
DHCP EXCLUDED
ADDRESSES-
DEFAULT
GATEWAY-
-/-/-
wireless network
VLAN
IP Addresses
Management-/24
interface(vlan 2)Wlc
AP manager-/24
(vlan2)WLC
Malonecarevoice-/24
(vlan3)
Malonedatacare-/24
(vlan4)
TABLE 4.4 WIRELESS NEWORKS
Switch VLAN Address
Switch INTERFACE
Switch-INT Fa0/1-12
Switch-INT Fa0/1324
TABLE 4.5 VLAN
VLAN’s
WLAN –VLAN6
WIRED –VLAN 7
GATEWAY-
IP Address
DHCP-
39
SUBNET Network-
4.10 Telephone system design
The 3CX VoIP server is designed to have a complete suite because it has it selected signalling
protocol and Codec inbuilt.
4.10.1CODEC
According to (3CX, 2013) the 3CX VoIP server uses G711, GSM and ILBLC. The G711 already
exists in our Client VoIP server.
4.10.2Signalling Protocol
3CX supports SIP and H.323 as its signalling protocol.
4.10.3 Dial Plan Design
The extension numbers will dwell in the 1000 series. The extension of every staff will range
from 1000, 1001, 1002 and 1003 and so on and so forth. 8001 is used for the autoattendance, 8001 for group ring, 8002 for call distribution, 7000 for call conference.
4.10.4 Telephone features design
The telephone features needed in care home were stated by the client and are already
explained in our chapter 2. These features are:
TELEPHONE features
BASIC SIP to SIP CALLS
Voicemail
Auto Attendance
Call recording
Call distribution
Call Conference
TABLE 4.6 TELEPHONY FEATURES
4.11 Design for WLC
(SSID)
Malonenetwork: this SSID are mapped to Vlan2 created on the router, the management
Vlan2 will administering the LWAP.
Malonecarevoice: this interface will be mapped for voice, on vlan3 in the router
Malonedatacare: This SSID interface will be dedicated for data and is mapped to vlan4.
4.11.1 Security of Wireless LAN
Wired Equivalent protection (WEP): Will be security module to protect the malonenetwork
SSID.
Wireless Protected Access (WPA1+WPA2): WPA will be security module for
malonedatacare SSID mapped for the vlans for data.
40
802.1x: The 802.1x using a RADIUS server + Cisco Centralised key management (CCKM) will
be used for the Interface for voice (malonecarevoice) to further protect Wireless LAN to
enable fast secure roaming.
4.12 WLAN QoS Design
The WLAN QoS design for the network infrastructure, on the Wired Network the Diffserv
model is chosen. The Auto QoS is used in this design for ease of implementation in the
network. The WLC is connected to a switch port on the Layer3 switch/router where the
VLANS created on the router/layer3 switch will use the on trunk on an interface created to
route traffic to the WLC. Our design will have CoS value where the trunk interface on the
router/switch that links the WLC. While the switch where the AP are connected will be
design to DSCP values where- - network) interface on the WLC for
voice.
The WMM as stated in chapter3 has a mechanism which uses traffic profile by using the
access category or priority level which is already installed in WLC and is deployed to fit voice
needs.
The WLC supports these profiles
Voice/platinum —guarantees QoS for voice over WLAN
Video/Gold— ensures quality video applications.
Best Effort/Silver—Supports normal bandwidth for FTP users this is the default
setting.
Background/Bronze—ensures low bandwidth for low application
Our Voice client’s which are mapped to- network in Vlan3 on WLC
(malonecarevoice) will be configured to platinum profile on the WLC.
. The QoS profile platinum for voice, IP headers of packets that encapsulate the LWAPP
packet from WLC to AP, will have the Platinum value (though the IP headers that cover the
originating packet from the 3CX have High priority).
RECOMMENDATION
The requirements needed to design the VoWLAN for the client has been listed in this
chapter. However for calls to public network such as PSTN and GSM, a VoIP provider or SIP
gateway is required to link the traffic from the client network to these networks.
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CHAPTER 5
System Implementation
5.1 INTRODUCTION
In this very chapter we will demonstrate the deployment and configuration of the design
referenced in chapter 4. The configurations to be implemented are the WLAN configurations
which include the SSID, AP, VLANs, management and security. While the VoIP Server and the
radius server will be implemented on the wired network. The configuration for interfaces
and their command will be shown to give an overview of how wireless LAN are been
deployed.
This chapter covers the objectives 3 in the terms of reference.
5.2 Network Implementation
5.2.1 Routing configuration: The client care home is a 1 site deployment, the router/layer3
switch as a DHCP server. The router configurations below enables the router interfaces to
go up and open ports for communication, the IP address; Net mask, No SHUTDOWN
command and configuring of DHCP for implemented when configuring a physical interface.
FIG5.1 routing configuration
5.2.2 Trunking configuration
This configuration allows an interface to enable routing. However, configuring an IP address
and Net-mask on this interface is possible but then an interface VLAN has to be configured
then linked to the Fa0/1 interface a physical interface on the layer3 switch. The photo text
below depicts the trunk configurations that were deployed for all the VLANS created on the
router for the WLC.
FIG5.1Trunking configuration, Chiedu, 2013
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5.2.3 DHCP server configuration
The router/layer3 is a DHCP server. The 1st -10 subnets of the configured interfaces
addresses in our client’s WLAN will be excluded as unique needs may arise. The DHCP pools
are configured to dynamically give IP addresses to devices of staffs in our client’s care home
WLAN devices with different SSIDS’. The SSIDs’ created on the WLC for the access points
will pass on IP addresses to a client devices based on the SSID the client device authenticate
to, and this SSID’s are map to these various DHCP Pool. The below is the different DHCP
configuration
FIG5.3 DHCP router configuration, screen shot, Chiedu, (2013)
Option 43 hex f104c0a80203
Option 43 is been understood by the LWAP as the AP-Management IP Address. Hex means
hexadecimal (base 16) and is an alternate numbering system to normal decimal system. The
f104 code means (f1) is alongside an IP address with four bytes in length (04). Code
c0a80203 is the IP address- of AP manager in hexadecimal. Every IP address has
its code in hexadecimal.
5.2.4 Switch Configuration
The configuration in the Image below shows how the switch is shared into 2 segments on
the layer2 access level. The decision to segment the ports on the switch into 2 is to make
one segment of the switch for the wireless LAN and the part of the switch for wired
network. The wireless LAN segment of the switch is where devices like the AP will be
43
connected so that devices can be connected to the network. Likewise the Wired section on
the switch is for connecting workstation for servers, or other application.
Fig 5.4: Switch configuration showing allocation of ports on the switch.
5.2.5 WLC configuration
The lists of configuration on the WLC are the IP address allocated to WLC, net-mask, IP
management, DHCP server and gateway address. Though the CISCO WLC requires a user to
login, a configuration for user login credential is also deployed so that when the WLC is to
be accessed from the web interface it prompts the users or the administrator for user name
and password. Finally, accessing the WLC through a web interface a configuration is need
for this possibility. The image below shows the WLC configurations. This shows the virtual
interfaces address discussed in chapter 4 it makes web communication and mobility
possible which is primary case in our implementation and its unique for every mobility
group. The virtual interface used is 1.1.1.1 for its address. The radius server address must
be shared with the WLC and vice-versa. A shared secret is to be shared between the Radius
Server and the WLC. The decision to use apple was chosen by the client.
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Fig 5.5: WLC configuration.
The configuration in the picture below shows web functionalities and enable telnet sessions.
This means when a web browser page is open on the host device that administers the WLC
on wired network typing- which is the IP address of WLC Manager on the
browser will the prompt access to the WLC in order to further configuring process which
usually demand for user credential of the WLC.
45
Fig 5.6: WLC configuration.
5.2.6 Access Point Deployment
To deploy access appoints in this experiment, Two assess point are used to connect the
switch and will be kept and far ends of the laboratory to simulate roaming. The access
points are connected to the WLC through the switch and it appears on The WLC Monitor
module that 2 access points have are joined to the network.
FIG 5:7: showing the connected access point on the WLC monitor
5.2.7 WLC interface configuration
In this module, The VLANS configured on the router are now configured as interfaces to pass
different type of traffic that workers intended using. The interface dedicated for voice is
showed below
46
The next image explains what is needed to create another interface. Decide on the name of
the interface like I gave this interface (malonecarevoice) as it’s the interface to traffic voice
and matches the VLAN I created on the router.
FIG 5:8 showing the created interface on the WLC for voice
CLICK the apply button and you are prompted to setup the interfaces configuration. This
setup configuration is the same for all the interfaces that are created on the WLC. The next
screen below shows the necessary rows to be entered which are IP Address of the interface,
Net-mask, gateway, port number and the DHCP server address.
FIG 5:9 showing the IP address information of the voice interface.
This below screen shot shows all the various interfaces for the sponsors WLAN
47
. FIG 5:10 showing the Different interfaces on the WLAN
For the interfaces to be used by wireless devices of the client’s care home workers, SSID are
created to link the interfaces. The below images describe means of creating new profiles
and SSIDS
FIG 5:11 creating new profile network
The below show how to navigate to creating the new profiles
48
FIG 5:12 Navigation to creating new profile
The below shows how the voice SSIDs for voice is been created,
FIG 5:13 creating profile for voice and SSID
The graph below show how the SSID configuration is made. This shows how the SSID is
mapped to the interface. This will help end user’s to know the network to logon to and this
will be used to differentiate traffic security and QoS policies.
FIG 5:14 creation of policy on the SSID
In summary, the graph below shows what all the SSID created look like.
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FIG 5:15 LIST of SSIDs
5.3 Roaming configuration
The image below shows the Radio Resource Management parameters for our roaming client
devices on the 802.11b Radio frequency on the WLAN. The same parameters are used in the
802.11a and 802.11g. However, the parameters are left at default. Nevertheless, these
parameters are to be altered during the course of testing the voice application that will run
on the WLAN. The minimum RSSI is when a user’ roaming devices RSSI drops below -85dBm
as we intend roaming voice it won’t associate with any AP, it waits till its finds a better AP
with better signal strength. The hysteresis is valued in dB and it means that a roaming
device have to weigh how strong the signal of the neighbouring Aps are before considering
roaming to it. Scan threshold value means that if the RSSI value of a client below 72dBm the
device starts scanning for another access point. Transition time is the time taken for a
device to find an AP with better signal strength before it authenticates the AP.
FiG 5:16 client roaming configuration
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The WLC 2100 series is limited with the RRM module in which a lot of parameters can be
altered but with the roaming test is still carried out.
5.4 Security Configuration for wireless LAN
5.4.1Radius server
For the wireless LAN security for the voice VLAN, we deployed a RADIUS server to enable
user authentication the 802.1x. The graph below will shows the how the RADIUS server is
deployed. The RADIUS server functions by creating a certificate for the users of the network
and this certificate will function when there is a shared secret between the WLC and the
RADIUS server.
This Fig5:17 shows that a certificate has been created for users
Remember earlier in this chapter that when configuring the WLC, the RADIUS server IP
Address was configured with a shared secret. Now the WLC information needs to be passed
to the RADIUS server with the same shared secret.
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This Fig5:18 shows shared secret between RADIUS and WLC
The graph below shows how to create users identification and password to enable a user to
authenticate the wireless LAN. The RADIUS communicates with the WLC to prompt a user to
submit his credential before they can have access to the network.
This Fig5:19 Graph show creating user information.
When the RADIUS server starts running, the WLC now has the RADIUS Server address and
shared secret we can now create the 802.1X authentication + CCKM on the voice VLAN
profile so when its SSID shows beacons to users it requires an authentication. The next
graph shows the RADIUS DEPLOYMENT on the WLAN network dedicated for voice.
52
FiG5:20 showing 802.1X CONFIGURATION.
WEP was configured on one of the other interfaces with for the (Malonetwork) and the
WPA2 for (Malonedatacare) for the other WLAN network (SSIDs). The next graph shows the
summary of the security of WLAN
FIG5:21 showing summary of security of the networks
53
The graph shows with a WI-FI spectrum analyser the Summary of the WLAN from an
external perspective. With the pointers description it shows that the SSID (malonecarevoice)
is secured by the WPA2 enterprise security with -58DBm one 1 channel and 61 on another
channel, since 2 access point were the deployed for this deployment, it is seen that one
access point is making using of one channel and the other access point is using another
channel all which are functioning on the 802.11g radio frequency. The rest of the SSID used
can be seen in below with their different security deployment.
FIG5:22 Using INSSIDER software to Analyse available networks
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5.4.2 Further security
I further enabled security by configuring SRTP on host devices 3CX SIP softphones, so that
when voice traffic travelling is protected in real-time to safeguard against eavesdropping on
call session.
FIG5:23 securing sip client
5.5Configuration for VoIP
In order to implement the VoIP server on the network, I built a windows 7 virtual machine
and installed the 3cx phone system inside it in order to work with VMware in the lab. The
VoIP server will connect to the wired LAN section of the switch and the VoIP server IP is
address-. The voice application will run in order to enable calls with the- on the wireless network.
5.5.1 Configuring of extensions on the phone system
For carers in our clients care home to communicate, a dial plan must be created on the 3cx
system. This will entail configuring of extensions; so that other telephone features can be
enabled.
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FIG5:24 configuring extensions
5.5.2 Configuring SIP client
The SIP client can be used on different SIP soft phone. However, since the VoIP System has
its own soft phone, we will be deploying 3CX softphones. The 3cx is configured either by
setting it on auto provision or manually creating the SIP client profiles. The both methods of
creating the SIP client must match the profile extension created on the 3CX telephone PBX.
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FIG5:25 soft phones
As soon as the soft phones are connected and to VoIP server, the below graph shows that
PBX that the SIP phones are registered.
FIG5:26 Summary of registered phone.
5.5.3 Configuring PBX Telephone features
Some of the telephone features such as the auto attendant is implemented and can be seen
on the VoIP server activity log image below. Other implemented features will be found in
the appendix section for the configuration of the telephony PBX features. The below screen
shots shows 8000 is the extension for digital reception/ auto attendant has be created and it
is a virtual extension because it is not associated with any physical phone.
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FIG 5:27 configured features on 3cx server
5.6 WLAN QoS Implementation
QoS on the Layer3 switch
To accelerate WLAN Quality of service deployment, simplification of human user interface is
required. In Deploying QoS in our client’s network I deployed Cisco Auto-QoS to reduce
errors. The configuration ‘’mls qos trust cos ’’ is used to deploy QoS that is implemented on
the router/layer3 switch port interface trunked to the WLC.
On the Interface Fa0/1 the (mls QoS trust Cos) implemented, will enable creation of class
maps, and then apply policy maps, before traffic marking to give priority to the voice packet
then it applies low latency queuing technique so that when there is limited bandwidth the
voice traffic can go through since it’s the priority traffic is voice. QoS ‘’TRUST’’ interface
configuration means that a boundary is set to where the switch is going to trust the Cos
label that it receives and treat traffic with respect to the CoS values.
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QoS On The access Switch
The switch that connects the AP interfaces and the interfaces that connects the VoIp servers
used in the network, The mls QoS is also used, but this time the “Trust DSCP” is
deployed.The mls Qos “Trust DSCP” on the interfaces connecting the AP is basically
deployed so that the interfaces of the AP on the access switch can trust the policy set by the
WLC for the AP. Since there is no CoS marking within the LWAPP frames from the access
points, the switch have to trust DSCP of packets of LWAPP coming from the AP.
Fig 5.28 QoS INTERFACE CONFIGURATION FOR AP ON SWITCH
The WMM QoS on the WLC the malonecarevoice interface gives priority to voice by ticking
platinium and enabling WMM policy. So therefore, on this interfaces voice is the priority
traffic. Other traffic will be degraded at the expense of voice performance.
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Fig 5.29 QoS INTERFACE CONFIGURATION ON WLC FOR VOICE INTERFACE
5.7 Work station and device configuration
On the wired network ip address is manually configured for devices, such as the servers and
work stations.
The devices on the wireless LAN ip addresses are given by the DHCP server. The wlc
monitors all devices associated with the AP on the WLAN.
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Fig 5.30 DEVICE REGISTERED WITH WLC
5.8 CONCLUSION
This chapter addressed all the necessary implementation processes in the network so as to
verify the success of artefact of my sponsor.
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CHAPTER 6
6.0 TESTING
This chapter is dedicated to test various procedures for the already implemented artefact
delivered in chapter 5 to ensure that the functions of the built prototype is working according to
the wishes of the client.
The test chapter is categorised into different sections network connection, roaming test, security
test, QoS tests and telephony features verification. The much needed screen shot test-result are
shown in this chapter as proof of working prototype while the rest of the screen shot will be
shown the appendix.
6.1 Network connectivity test
The network connection test verifies and confirms that the devices needed to setup the network
are rightly connected and in this case the wireless LAN can reach the wired network. The graph
below is the work station used to administer the WLC in which from the command prompt
menu, it pinged the interface for voice -) created by the router that will be used by
the WLC to traffic voice
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FIG: 6.1 showing network connectivity to the interfaces on the Network
Pinging the two servers, the radius server with IP address- and the VoIP server
with-. We remember that all devices on- network are handed IP
address by DHCP. The 1st device that gets an IP address from the voice interfaces as soon as
it associates with an AP gets-.
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FIG: 6.2 showing network connectivity to service interfaces and server on the Network
The screen shot below shows that wireless LAN communication is present in the network, as
we can see that 802.11 protocol carrying LWAPP encapsulated packets. It can be seen that
as the SSID broadcast beacons so that devices seek association to the WLAN, The 802.11
protocol is seen running on the WIRESHARK monitoring software
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FIG: 6.3 showing 802.11 protocol running
6.2 Telephone Verification
To verify that the SIP phones have been registered, the client will check on the VoIP server log and
will confirm that the SIP phones have been registered. The below screen shot shows the SIP Client
that have been registered. The client can verify that a SIP device has been registered from the
VoIP server log. The VoIP server is showing that SIP client 1003 is registered and its IP address is-, which is the IP address the DHCP assigns to every user that is legible to join the
Voice network. Also the client can see that a user at 1002 is registered and is using an IP address-.
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FIG: 6.4 showing SIP phones have been registered in VoIP server showing client device IP
address
6.2.1 Call setup
The image below shows the activities in setting up calls between two SIP clients. My client will
observe from the call server log that extension 1003 with IP address- has sent a
call request to VoIP server- to reach extension 1002 with IP address of-. The VoIP server will allow communication at port 5060.
FIG: 6.5 showing Call setup
6.2.2 To verify the SIP to SIP call session
The screen shot below shows that there is an on-going call session between the two SIP clients
1002 and 1003 in the network. The client can verify which users in the network are calling as the
extensions created has the name of the user. This is another attribute of 3CX while creating an
extension.
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FIG: 6.6 showing Call verification
6.2.3 Verification of Auto-Attendance /Digital reception
The sponsor requested for a helpdesk/digital reception. The digital reception number for the
client’s care home is 8000. The screen shot below is the server log activities of how an
extension called the helpdesk. The screen shot shows that the digital reception has been
contacted from extension 1004 and has prompted the caller to the available options in the
menu. From the screen shot the client will identify that the digital reception was dialled, it
prompted the caller to the available option, the user opted for the available option, which was
ringing extension 1003 which was not available at that moment and it entered the voicemail of
1003.
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FIG: 6.7 digital reception/ auto attendant verification
6.2.4 Voicemail
The voicemail option was tested by extension 1004 calling extension 1003. The 1003
extension was busy at the time extension 1004 called, and then the voicemail of extension
1003 prompted the caller (1004) to forward a voice message to the voicemail at 6666. The
voicemail 6666 is where extension 1003 can retrieve the voice message by supplying its
password to the voicemail number.
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FIG: 6.8 voicemail verification
6.2.5 Group ring
The group ring was tested by dialling the extension 8001; the client will identify from the
server log all the extension/users that are part of the call group ring. From the server log
once 8001 is dialled all the members of the group ring will start ringing.
FIG: 6.9 Group ring verification
6.2.6 Call Queue/ Call distribution
To verify that the call queue/ call distribution was implemented, The client can verify from the
screen shot below from 3cx server log that the call distribution moved calls from between
extension that were are part of the call queue. The screen shot shows that after extension
1003 was called and it was not available, the call to move to extension 1006 and after
extension 1006 was busy, the call queue took it to extension 1005. The Hunt random start
strategy was deployed for the call distribution. Any extension randomly can be picked with this
strategy.
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FIG: 6.9 call queue verification
6.2.7 Call conference
The below screen shows that two extension joined a conference call at 7000, and a call
conference is going on. The two extensions are in the call conference could also have
multiple person to join conference.
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Fig 6.10 call conference verification
6.2.8 Call recording
The screen shot below shows that audio files have been recording a voice conversations
between two extensions 1002 and 1003 concurrently.
Fig 6.11 call recording verification
6.2.9 Video call
Since SIP supports video, video call was implemented and can be confirmed from the screen
shot below that a call session between extension 1003 and extension 1004 with video.
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Fig 6.12 video call verification
6.3 ROAMING TEST
To verify the mobility is working properly, I used the monitor module on the WLC to test
roaming within the lab. . My client can use monitor modules on the WLC to keep track of every
device that is associated with an Access point in the WLAN and have their mac address details.
The test below was done on the 802.11b and g because most of the devices used in the
practical were not 802.11a capable, also the WLC 2100 series used in this experiment was not
802.11n capable so there was a restriction to the channels I could operate on
For the roaming test, The 2 AP were kept far on the both ends of the lab, Then a call session
starts between 2 client devices that have associated the- network of which this
interface on the WLC is dedicated for voice. During the commencement of the call between the
2 devices with MAC address (00:24:21:ce:36:2c) and (90:A4:de:76:4b:89), the two devices were
associated with 1 AP named LWAP1. The screen shot below shows the devices and the AP they
are associated with during the call before roaming.
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Fig 6.14 shows MAC address of devices associated with the LWAP1.
During the call session the device with MAC address of (00:24:21:ce:36:2c) is associated LWAP1
started moving towards the other side of the lab, and as it was moving away from the its AP,
During the movement of the device from the other end of the lab, the call session wasn’t
terminated, though there was a bit of delay because of association delay to the next access point.
Fig 6.15 shows that the signal strength of the device on the maloncarevoice is SSID
is degrading
. However, during the roaming of the device, I found that on the WLC, the MAC address of the
device has moved from the LWAP1 to LWAP2. The screen shot below shows that device with
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MAC address (00:24:21:ce:36:2c) moved from LWAP1 has moved to LWAP2 compared to
previous screen shot.
Fig 6.16 shows MAC address (00:24:21:ce:36:2c) is now on LWAP2 and moved from LWAP1
The image below shows the signal strength level during the association of the device from
the LWAP1 AP to the Lwap2. The device started losing signal strength as it started roaming
to the next AP, however as soon as it associates the next assess point the signal strength
level increased.
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Fig 6.17 SHOWS SIGNAL STRENGTH DURING ROAMING FROM 1ST ACCESS POINT TO THE
NEXT ACCESS POINT
6.3.1 Second test for roaming
I tried to simulate another event for roaming/ failover test by tripping off one of the Access
points. The below screenshot shows the 2 devices associated with 1 AP before the tripping
off this particular AP.
Fig 6.18 shows the AP and the devices associated to it before roaming
After I tripped off the LWAP1 AP I found out on the WLC monitor, that the 2 devices associated with
AP has moved over to the other LWAP2 access point. The below screenshot explains that the devices
successfully roamed moved over to the LWAP2 but could not roam voice. The call was terminated
after some microseconds after the LWAP1 access point was tripped off. This occurred because voice
gives a delay budget of 100ms and cannot tolerate any amount of delay that exceeds that.
Fig 6.19 shows the LWAP2 IS the AP the devices are associated with after
roaming
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The below screen shot explains from wire-shark that during the roaming of the devices a call session
was going on between the devices with IP address- was communicating with- but the call was terminated after the trip off of the LWAP1, however roaming data may
survive this failover because it is not sensitive as voice.
Fig 6.20 call session
Security testing
In order to verify security of the RADIUS server deployed on the voice interface on the WLC for the
WLAN, I deployed a monitoring work station using Wireshark to monitor all the activities both on the
wireless LAN and the WIRED LAN. The below screen shot shows access challenge request by the
RADIUS server to the WLC’s access points. The image below also shows that after the user has
entered its correct credential the LWAP sends the Access Challenge Request to the WLC to inform the
RADIUS server that a user wants to authenticate the network. The RADIUS server acknowledges and
sends an Access Accept to the WLC to inform the AP to allow the user to associate the WLAN.
Fig6.21 RADIUS server verification
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6.22 Verification of SRTP
I used wireshark to monitor the activities on the network. Before securing the sip clients with SRTP,
I was able to eavesdrop on a call session conversation between two clients on the VoWLAN through
the Wireshark telephony decode module. The below graph shows that the conversation was not
secure and can be listened to
Fig 6.22 shows that SRTP verification has not been implemented
After securing the sip client with SRTP, during a call session I tried to use the decode module on
wire-shark to eavesdrop on a call session but no conversation could be heard. On The graph below
shows how SRTP was able to defend against eavesdropping on calls and shows the IP address that
were used in calls.
Fig 6.23 shows that SRTP verification has been implemented
The client can view how the Voice call was secure in the below wire-shark screen shot. Wire-shark
analyses that the two SIP client with IP address- and- are secured with the
SRTP protocol. SRTP aids in to securing our client voice calls.
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Fig 6.24 Wire-shark shows that SRTP verification has been implemented
6.23 Testing WLAN QoS
Recall that quality of service is used to guarantee a certain type of traffic at the expense of other
contending traffic. As requested by the client, voice is the priority traffic. In order to verify the QoS
implemented is working, a test was carried out by using software named JPERF to generate traffic
to congest the wireless LAN link. Recall in chapter section 3.3.2 that 802.11g data rates is 54Mbps
so therefore flooding the link with 100Mbps will affect the call quality . An individual score sheet
will be handed to different individual to be used to assess the voice quality of the call based on
individual opinion , this assessment will be judged both when the wireless links is congested
without QoS implementation and when the wireless links is congested with QoS implementation.
This assessment is referred to as Mean of Score (MoS). The MOS sheet has a likert scale from 1-5
to grade QoS in terms of how good call quality are.
Score
5
4
3
2
1
Label
Very Good
good
Fair
poor
Very poor
TABLE 6.1 MOS
The QoS is tested while devices are roaming and secured with the CCKM+802.1x
6.23.1 Link Congestion
To congest the network I used 2 client devices on the wireless network of- network to
inject UDP traffic on the wireless link. Jperf functions in a server/client mode where one of the
devices used in the WLAN acts as client and the other device acts as a server. The client device was
used to flood traffic to the server device to suffocate the wireless link. The client device will have the
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address of the server. The JPERF server device is also used was a SIP client in the experiment. UDP
traffic at 100mbps was used to flood the link
FIG 6.25 JPERF SENDING TRAFFIC ON THE WIRELEESS LINK
Subjective MOS RESULT
6.23.2 before QoS Implementation
6 of my colleagues volunteered to test QoS for the Client’s system. Before deploying QoS, The
volunteers were told to have call conversations making use of phones on network and roaming
round the lab, during the call, heavy traffic of 100Mbps was injected into the wireless links using
Jperf. The MOS sheets were handed over to them to tick their opinions on the quality of the call
conversation with scale preference 1 -5 listed above. The feedback sheets from the volunteers are
seen in the appendix.
The 6 volunteers values generated were: 2,1,1,1,2, and 1
The MOS = sum of value /number of participant
2+1+1+1+2+1= 8
8/6 = 1.33333
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The MOS at 1.3333 means that quality of the voice calls was very poor. However roaming within
the access point would have further degraded call quality. One of volunteer noticed that his SIP
client has disconnected from the network.
6.23.3After QoS
The test was repeated by the same volunteers again, however this time the test was repeated with
QoS implemented on the WLC and switches described in the implementation chapter. The same
process of collecting score sheet was done again.
The 6 volunteers values generated were: 4,4,5,4,4,5
The MOS = sum of value/ number of participant
4+4+5+4+4+5 =26
26/6 = 4.333
The MOS at 4.3333 means that the quality of voice calls was good. This implies that QoS was
successful and proved an improvement to when QoS was not implemented.
6.24 ISSUES ENCOUNTERED
The challenges encountered during course of the Implementation, testing of the built the
Prototype.
1 Positioning of LWAP: The laboratory where all the testing for the client’s prototype was done was
not big enough to accurately measure AP boundaries for handover/handoff purpose. The placing of
AP’s horizontally would make signal strength measurement unstable and that was the only choice
to deploy APs in the lab other than placing access point horizontally in the lab. WLC 2100 did not
have enough Radio Resource Management modules to alter several parameters. Also the exact
point and time of handover/hands-off of call cannot really be measured as the WLC does not record
real-time application exchanges.
2. Cisco suggests 802.11a for voice because it has 20 non-overlapping channels operates at 5GHz.
802.11a channels is space out 20 MHz s apart with a RF spectrum bandwidth at 20 MHz. However,
because of the devices used in building this prototype for client was not IEEE802.11a enabled. I was
left to operate at 802.11b and g. The 802.11g had other competitor networks that caused cochannel interference because their RSSI were stronger than the RSSI of the clients WLAN. According
to 60% of the volunteers that assisted in testing the Quality of service said that their score sheets
was marked at 4 after QoS was implemented because they heard echoes in their conversation. This
echo was caused by the co-channel interference from their neighbouring networks.
80
FIG 6.26 SUMMARY OF CO-CHANNEL INTEFERENCE
FIG 6.27 SHOWING CO-CHANNEL INTERFERENCE UPDATE
3 I was limited to software to test objective QoS analysis. Where by software can analyse call
quality and give feedback on the analysis. Most of the software for QoS analysis have licenced keys
81
6.25 RESULTS
This chapter verifies that the client’s needs have been satisfied by testing the implemented
prototype deployed in chapter 5
Test
Network Connectivity
Success
There was connectivity between the wired network and the WLAN. The
mobile devices were also able to connect the servers.
Roaming
Devices in the WLAN were to roam between access points even while
calling
Telephone registration / VoIP
telephone features test
Basic Sip to sip calls achieved. The features needed in client’s care home
organisation were successful deployed.
Security
Securing the WLAN was successful with 802.1x, WPA2 and WEP
Also securing the voice call was also achieved
Identifying how healthy call quality was carried out through the MOS
Which verified that QoS implemented was successful after the network
was congested with high traffic.
QoS
TABLE6.2 result
82
CHAPTER 7: EVALUATION
7.1 CHAPTER INTRODUCTION
This Chapter assesses and evaluates the prototype VoIP system built against the
requirement my client stated in the terms of reference with the project objectives set out in
section (1.5) in chapter1. In order to check if the project was successful or not, the
objectives stated in the TOR and the client requirement will be analysed and will be used to
assess the project and see if the objectives set was satisfied.
7.2 Evaluation on the prototype
Client Requirement 1: An Implemented VoIP system on a secured Wireless LAN which is capable
of call functionality within the client’s office premises.
The Built Prototype my sponsor requested can be seen in chapter 5 as evidence that VoIP
PBX was deployed on WLAN. The built system was design to fit my client organization size
which was a low cost deployment strategy. Most VoIP PBX features are typically required to
meet organizational needs and give value added services to the organization, the listed
agreed VoIP features the client requested for were chosen to meet the needs of an old
peoples home. The telephone features my client required was designed in chapter 4,
implemented in chapter 5 and tested in chapter 6 to verify that the built prototype is
functional. Voice over WLAN was analysed in chapter6 with screen shots from server log of
the VoIP PBX and wire-shark which verified that SIP protocol was present in WLAN. However
during the testing, because of several stronger WLAN within the area of deployment of the
prototype, these WLAN networks that were present in the environment struggle for
channels with my client’s network, from the MOS test the very best voice quality was not
attained.
The client’s WLAN was secured by implementing 802.1X (deploying a RADIUS server) WEP,
WPA2+ and CCKM using the WLC and then for securing Voice, SRTP was implemented and is
shown as proof with annotated screen shots that analysed the security deployed on the
WLAN using Wire-Shark analyser in chapter 6.
The Screen shots in chapter6 showed the activities of the WLAN through the WLC, the
screen shots showed the monitoring of devices on WLAN. Also my client was able to have a
call conversation with the prototype delivered during my demonstration in the lab.
Client requirement 2: Research VoIP over Wireless LAN.
The client requested for a research chapter that critically analyses VoIP on WLAN that fits
the need in her organization. The evidence presented in the whole of chapter 2 and 3 shows
critical analysis of VoIP over WLAN needed in a care home. Chapter 3 showed how VoIP over
WLAN is achievable, with the needed solutions to set a VoIP system on a wireless LAN.
Client requirement3: Evaluate design and build a prototype VoIP system.
My client requested an evaluated design of the prototype VoIP over WLAN system from
which the real VoIP system will be built. The concept of the design was basically done for
small enterprise like that of my client which was evident in chapter 4. The design of the
prototype was done to meet mobility needs also. The implementation of the design was
83
successfully deployed as shown as proof in chapter5 with necessary explanatory screen
shots needed in building a VoIP over WLAN system.
Client requirement 4: Evaluate the prototype as regards to Quality of Service.
Different analysis was put together in order to test how voice quality will be attained when
unfavourable condition like congested links occur in the built prototype network. The client
can see from the WLAN QoS test session in chapter6 that QoS was analysed by using the
MOS technique to analyse the quality of call when heavy traffic congests the wireless links.
Without deploying QoS the MOS was 1.333 while after QoS was deployed the MOS was
4.333. This shows that QoS deployed was effectively carried out and was confirmed.. The
client feedback in the appendix session confirms and expresses his satisfaction towards the
built product.
7.3 Evaluation on Project Objectives
This session evaluates the entire project against the objectives that were set out on the TOR
Project Objectives1: To research features in VoIP over WLAN relevant to deliver
communication needs in old people’s home.
To fulfil the sponsor’s requirement of implementing VoIP on WLAN in his organization, with
the aid of peer reviewed journals from well-known sources such as IEEE and Cisco, a critical
review was done in order to analyse VoIP features that are needed in an old people’s home.
The telephone features where investigated to see the purpose it will serve in my client’s
organization. The proof is seen in chapter 2. The critical research proved worthy as the
necessary features were listed and deployed on the built prototype to serve communication
needs required by the sponsor care home. The table below summarizes the objectives that
have been met.
Objectives
To identify Vowlan features that can Chapter 2.6
be delivered in our client Old
People’s Home
Deliverable proof
VoIP telephone features that can be Chapter2.7
delivered in our client Old People’s
Home
Table 7.1 evaluation table
Project Objective 2: review literatures on roaming with QoS within access points on WLAN.
This objective was thoroughly researched and critically analysed. The different sections in
chapter 3 critique VoIP on WLAN, critical analysis on roaming to effectively carry out
mobility functions for the client’s organization was reviewed with help of several combined
academic journals, tutors notes at the university and white papers. A comprehensive Critical
research on QoS on WLAN was reviewed in order to effectively carry out the
implementation. The proof can be seen in Chapter 3.27 -3.30
84
Project Objective 3: Design and implement a roaming prototype VoIP system over WLAN
using 3CX
The built prototype was designed to meet industry standard, though at the same time it was
designed to reduce cost. The design concept was to fulfil roaming, security and QoS. The
design for roaming is shown as evident with annotated screenshots in chapter 4.7 for design
and the implementation 5.2 and also the 3CX PBX was adopted in the design to meet the
needs of the client; however the design for roaming suffered challenges of limited options
Radio Resource Management module on the WLC 2100 used in the lab. Some of the RF
parameters couldn’t be altered to benefit voice. Though, other challenges occurred while
considering the placement of access points in the lab. Lack of 802.11a devices was one of
the shortcomings in the implementation of the roaming prototypes. Nevertheless the
prototype roaming system was designed and deployed.
Project objective 4: Test the prototype for roaming and Voice quality and operability
The tests and verification for roaming shown as evidence in chapter 6 was proof that voice is
capable of roaming within access point with call clarity without disconnecting the call which
is as a result of over overlap between cells of access points. Though a failover simulation for
APs was done to test if voice would roam, however it proved abortive because of amount
delay that occurred. The failover test could be obtained while roaming data. The use of
mobility group enabled roaming in the WLAN and also virtual interfaces helped to manage
roaming between APs
For voice to attain good voice quality while roaming across access point cell size should be
kept at -67DBm. Ideally multiple WLC is best practice for deploying mobility so as to handle
challenges of failover, however the client care home is not a large enterprise and especially
as regards to cost, one WLC was deployed during the test for roaming. For test for voice
Quality, QoS verification was carried out and the client can take notice of that in chapter6
that MoS test was used to pass judgement on if voice quality will be compromised if heavy
traffic congested the network but the deployed QoS proved sufficient to put voice as top
priority, to guaranty quality voice call. The environment where the built prototype was
implemented and tested had stronger wireless networks competing for channels and thus
co-channel interference occurred which partially contributed to echoes during call
conversation. Chapter 6 roaming and QoS section has clear evidence that roaming and voice
quality where obtained.
Project objective 5: Evaluate prototype on best industry standards
The prototype built for client can be assessed in the whole of chapter 6. The built prototype
VoIP system has the capacity to function both on the wired and the wireless local Area
network. The essence of deploying the VoIP PBX on a WIRED network rather than the WLAN
is to allow communication on both the wired and the wireless LAN in the client’s
85
organization and also to avoid compromising availability. Deploying a server on a wireless
LAN may in some occasion disconnect from the network. Securing the voice VLAN on the of
WLC with CCKM and 802.1X allows the roaming WLAN users’ devices roam smoothly across
the access point with a few authentication delays during call mobility to avoid call
disconnect. The RADIUS was put in place to enable users’ authentication rather than device
using pre shared keys for the delicate voice traffic. Other industry standard deployment was
using the layer3 switch in the topology of the client network design for both routing and
switching functions as it reliable. Also a layer 3 switch was used in place of a router for
routing because when implementing QoS configuration on the 2811 router the HWIC
module does not support QoS configuration. Separation of voice traffic from data traffic by
placing the 2 traffics on different VLAN s was evident in chapter4 and chapter5 in the
implementation. The voice traffic interface -) was the interface that was secured
with 802.1X authentication. During the demonstration two PBX servers were used to
actually show that deploying a server on the WLAN is not best practice. The server used on
the WLAN often times disconnect from the WLAN and the entire sip client also
disconnected. However the PBX on the Wired network remained connected all through the
session.
Project Objective 6: Give recommendation for future improvement
Recommendation for further research is discussed in the next chapter which is the
conclusion chapter of the dissertation, which will identify further area to explore in VoWLAN
communication
Project objective 7: To Present dissertation.
To present dissertation is an objective that requires a well-developed research, methods,
design, implementation, testing, analysis, evaluation and conclusion with academic
reference in one document. Other documents such plan for project and terms of reference,
and schedule is attached to this document. This documented dissertation should reflect the
aim of project that meets the sponsor’s need.
86
CHAPTER 8: PROJECT SUMMARY AND FUTURE
RECOMMENDATION
8.1INTRODUCTION
The overall set objective for this project was aimed at designing, building and integrating
roaming VoIP on WLAN. Different approach and methods were put together in order
understand the concept of realizing the VoIP on WLAN network system. At the
commencement of the project, the plan for project which includes the schedule and plan for
project evaluation was instrumental for time management and resource management
during the duration of the project, and played a key role in the success of this project.
8.2 Project conclusion
Introduction of the project in chapter1 saw the outlined needs of client that were to be
satisfied. While in chapter2 critically analysed the features of voice over IP on wireless LAN
needed in an old people’s home. Chapter 3 did critically analysis on the concept of VoIP,
WLAN and the integration of VoIP in a WLAN using 3CX, also review on roaming in WLAN
needed for client organization was researched and analysis on QoS was elaborated more on.
Chapter 4 focused the technical concerns of the design processes that were needed to
effectively deploy a roaming VoWLAN system in the client’s care home with proper analysis
to meet industry requirement in a small scale. Chapter 5 was the implementation of the
systems with regards to the design made in chapter4. Chapter6 focused on testing and
verification of mobility, security and voice quality to certify that the implemented product
worked as requested by the client. Chapter7 critically evaluated the built system for the
client against the objectives set out at the commencement of the project, to quantify if the
system reached the expectation of the client’s requirement. This chapter concludes the
project and gives recommendation and improvement for future work.
8.3 Recommendation for future Research
During the advancement of the project a number of areas were identified for further
research to benefit care home and health centres with the deployment of WLAN.
Deploying IP TV on a secured VoWLAN system for care home centres.
VoIP over WLAN system to support remote workers with 3G integration to
communicate with wards in a care home using 3CX
Deploying wireless surveillance systems with the integration of VoIP system
Deploying video services on WLAN in care centres to support remote location
communication with ward and health worker
Deploying Quality of Service on video on WLAN with VoIP
Securing VoWLAN using wireless Intrusive prevention systems
87
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LIST OF ABBREVIATION
Access Point---------AP
Internet Protocol-----IP
Media Access Control--MAC
Voice over Internet Protocol -----VoIP
Wireless Local Area Network------WLAN
Voice over Wireless Local Area Network---VoWLAN
Public Switched Telephone Network----PTSN
Private Branch Exchange-----PBX
Network Address Translation-----NAT
Distributed Control Functions ------DCF
Physical Layer----------PHY
Point Control Function--------PCF
Virtual Local Area Network---------VLAN
Secured Real-Time Transport Protocol------SRTP
Real-Time Transport Protocol -----RTP
Service set identity ---------------SSID
Institute of Electrical Electronic Engineering---- IEEE
Multiple-Input-Multiple-Output--------MIMO
Network Interface card----------NIC
Distributed System----------------DS
Basic Set Service------------------BSS
Extended set service -----------ESS
Wireless Local Area Network Controller-------WLC
Session Initiation Protocol----------SIP
User Datagram Protocol --------UDP
Transport Control Protocol---------TCP
RTP control protocol -----------------RTCP
Received Signal Strength Indicator---RSSI
Resource Reservation Setup Protocol----RSVP
Class of Service--------CoS
Shaped Round Robin------SRR
Mean Opinion Score----MOS
Enhanced Distributed channel Access--------EDCA
hybrid coordination function- HCF
94
APPENDIX A
1ST REVIEW ASSIGNMENT
Project Title
Deploying VoIP based system over a Secured WLAN in care home
using 3CX
Student Name (Student Id) UCHENNA CHIEDU-
MSc Title Telecommunication Engineering
Overview
The Market Demand for VoIP ( Voice Over Internet Protocol) is increasingly growing as
business Enterprise want to grasp and take advantage of this unified Communication as they
seek its cost effective benefits with guaranteed call Quality, as they wish to transport voice,
video and data across an IP network.
Business Enterprises both try to maintain wired and wireless network and want to maximize
the use of their Wireless LAN, with mobile IP Phones vendors in the Market, the need for
VoWLAN (VoIP Over Wireless Local Area Network) is the next area of concentration as it
imperative to match adequate wireless network with a VoIP system to assume quality voice
calls.
A care home company which wants to remain anonymous is looking at replacing its old
traditional telephone network as the maintenance cost has been a burden for the company,
the company wants VoIP as it a cheaper alternative for effective communication. The care
home is looking at the integration of a VoIP system on a Wireless local area network which
is aimed at call mobility within the care home premises to enable care taker nurses move
around having their daily routine work as they can attend to patient calls and enquiry while
being mobile
This project is targeted at integrating a VoIP system on a secured wireless LAN showing
voice call quality during mobility of which is to satisfy Quality of Service requirement.
Product to be delivered to client
A Prototype VoIP system that works on a secured wireless LAN with call functionalities, and
realtime communication over the WLAN.
95
Client requirements
An Implemented VoIP system on secured Wireless LAN capable of call functionality
within the Care home premises
Research VoIP over Wireless network
Evaluate design and build a prototype VoIP system
Evaluate the prototype as regards to Quality of Service
Constraints
Guidance.
Limited laboratory access for preparation and development of prototype system.
Resources
.
Direction from my supervisor.
Research Materials.
Cisco IOS Knowledge and skill set
3cx phone system
University laboratory tools, Routers, Switches, wireless controllers, access point.
Reporting to Sponsor
The project sponsor is a Care Home located in Nigeria, however wants to remain
anonymous. Recurrent advancement report will be prepared with scheduled skype
meetings and other requests via Email.
Sponsor Sign-off
Project Objectives
Guidance
1 To research features in VoIP over WLAN relevant to deliver communication needs in old
people’s home.
2 review literatures on roaming with QoS within access points on WLAN
3 Design and implement a roaming prototype VoIP system over WLAN using 3CX
4 Test prototype for roaming and Voice quality and operability
5 evaluate prototype on best industry standards
6 Give recommendation for future improvement
7 To Present dissertation
Statement of Research
96
To research VoIP on WLAN
Fitzpatrick, J., Murphy, S., Murphy, J. , 2011, An Approach to Transport Layer Handover of
VoIP over WLAN, Performance Engineering Lab, IEEE Computing, VOL 7, PP 74- 82.
Kim, B., Lee, H., Byeon, S., Lee, K.B, 2012, Enhancing QoS of Voice over WLANs, World of
Wireless Mobile and Multimedia networks, IEEE International Symposium, Vol 1. PP 1-9.
Khan, A., Smith, D., Hussein, S., Helgert, H., 2012, Performance analysis of VoIP codecs over
multi-rate EDCA, Consumer Communications and Networking, IEEE Computing, VOL8, PP
110- 115
Flaithearta, P.O, Melvin, H.O., Schukat, M., 2013, Improving VoIP over Synchronized WLANs,
Digital Technologies (DT), IEEE Computing, PP 6-13.
Villacis, D., Acosta, F.R., Laracueva, A.R., 2013, Performance Analysis of VoIP Services
overWiFi-based systems, Communications and Computing (COLCOM), IEEE Conference , PP
1 - 6Sfairopoulou, A., Bellalta, B., Maci´an, C., 2008, How to tune VoIP codec selection in
WLANs? , Communications Letters, IEEE Communications Society, VOL 12, PP 551 – 553
Jerjees, Z., Al-Raweshidy, H.S., 2010, Cross Layer Design to Improve the Handover Latency In
Multi-homed WLANs, Wireless Network and Communication Group, IEEE Conference paper,
PP 1-7
Briones, J.M., Coronel, M.A., Chavez-Burbano, P., 2013, Case of study: Identity Theft in a
University WLAN Evil Twin and cloned authentication web interface, Computer and
information technology (WCCIT), IEEE world congress on, PP 1-4.
Hu, D., 2007, Secure Roaming Optimization for VoIP in 802.11 MAC Layer, Convergence
Information Technology, IEEE Computing, PP-
Sung, Y., Lin, Y., 2008, IPsec-Based VoIP Performance in WLAN Environments, Internet
computing, IEEE computer society, Vol 12, PP 77-82
Radack, S., Kuhn, R., 2012, Protecting Wireless Local Area Networks, IT professionals, IEEE
Computer society, Vol 14, Issue 6, PP 59 -63
Loreto, S. and Romano, S. (2012) Real-Time Communications in the Web: Issues,
Achievements, and Ongoing Standardization Efforts. IEEE Internet Computing, 16 (5), p.6873.
Cisco, 2011, Is Your WLAN Ready for Voice? available on www.cisco.com
3CX, 2011, The Top 10 Advantages of a Windows Based PBX, 3CX White papers. available on
WWW.3CX .COM
97
Statement of Level of Challenge
This project is challenging because it requires thorough skills in using 3cx which is a VoIP
business solution, which is different from the open source asterisk VoIP solution which I
learnt to a very good level through the digital telephony module, though they have similar
operation but they are differences. Another challenge comes from integrating VoIP on
wireless local area networks. I was taught wireless communication where wireless local area
network was treated and the digital telephony module where VoIP was practically done on a
wired network in our experiments. I have a few knowledge on the integration of VoIP on
WLAN, although, skill acquired from modules I learnt has assisted in gathering basic
knowledge that is able to make carry this project.
Reporting to Supervisor
Report to: Phil Irving
Means of reporting : person to person meeting and email
Contacting frequency: every Monday.
Supervisor Sign-off
Signature
(this indicates acceptance of the scope of the entire project)
98
Date
99
NAME:UCHENNA CHIEDU, ID NO:-, Telecommunication Engineering
Task Descritption
Hours Total
Link to
Objectives
Task ID
MSc Project Schedule
PROJECT INITIATION
122
Actual Date
Estimated
Start Date
Estimated
End Date
Actual Start
Date
Actual End
Date
Planned Deliverables
PROJECT INITIATION PHASE COMPLETE
1
7
Project search and supervisor contribution
14
9/2/2013
9/3/2013
2
7
14
9/4/2013
9/5/2013
3
7
Contacting client for project proposal and requirements
Redefining topic to match clients requirement before proposal is
produced
14
9/6/2013
9/6/2013
4
7
search for research papers
12
9/7/2013
9/11/2013
5
7
Thorough review on topic
14
9/14/2013
9/16/2013
6
7
First draft of Terms of Reference (TOR) for supervisor
13
9/12/2013
12/9/2013
7
7
sickness leave
8
7
client and supervisor’s discussion on 1st draft of TOR
4
10/21/2013
10/21/2013
10/24/2013
10/24/2013
Correction from supervisor and client noted
9
7
Restructuring TOR from correction of 1st draft submitted to supervisor
5
10/24/2013
10/26/2013
10/25/2013
10/27/2013
Reviewed second draft for TOR
10
7
12
10/28/2013
10/30/2013
10/28/2013
10/31/2013
Deliverables for first review assignment
11
7
Schedule draft
Discussion with supervisor to sign off TOR and talk over drafted
Schedule
5
11/1/2013
11/2/2013
9/1/2013
11/2/2013
Terms of Reference signed by supervisor for 1assignment
12
NR
15
11/3/2013
11/4/2013
11/3/2013
11/4/2013
Document compilation for first assignment
13
Arranging documents for first review
RESEARCH PHASE
186
9/3/2013
07/092013
9/5/2013
Gathering ideas
9/10/2013
Requirement noted and produced in bullet point
9/11/2013
9/11/2013
Feedback from client and supervisor and proposal finalized
9/9/2013
9/14/2013
Academic journal found and textbook acquired
14/9/2013
9/17/2013
Full research and analysis on topic with q5 technique
15/9/2013
9/19/2013
FIRST Draft of TOR Completed
RESEARCH STAGE COMPLETE
14
1,2
session with supervisor and gathering of papers VoIP system And WLAN
14
11/4/2013
11/5/2013
11/4/2013
11/5/2013
research papers gathered and supervisor session successful
15
1
More research on VoIP system, and VoIP relevance in old people's home
14
11/5/2013
11/6/2013
11/5/2013
11/6/2013
VoIP protocols and VoIP notes taken down
11/7/2013
11/7/2013
11/7/2013
11/7/2013
16
2
Planning review submission
Meeting my supervisor and critical literature review on Wlan
architecture
14
11/6/2013
11/7/2013
11/6/2013
11/7/2013
Wlan architecture pre-notes layout done
17
1
Read and research on issue of VoIP on WLAN
14
11/8/2013
11/9/2013
11/9/2013
11/9/2013
references created for VoIP QoS
18
1
More research on QoS on VoWLAN and session briefing with supervisor
14
11/10/2013
11/11/2013
11/10/2013
11/10/2013
QoS on VoWlan materials gathered
100
19
2
more research on WLAN
12
11/11/2013
10/12/2013
11/11/2013
11/12/2013
Wlan materials gathered and literature review notes jotted.
20
1
Review literature on common security technique in VoWlAN
14
11/12/2013
11/13/2013
11/12/2013
11/13/2013
security technique papers in VoWlan gathered
21
2
continuous research on common security technique in Wlan
12
11/13/2013
11/14/2013
11/13/2013
11/14/2013
security solution notes jotted for draft for literature review
22
1,2
session with supervisor to discuss reviewed papers
3
11/14/2013
11/14/2013
11/14/2013
11/14/2013
supervisor review on papers noted and correction follows
23
2
research papers on roaming
10
11/15/2013
11/15/2013
11/15/2013
11/15/2013
handoff/handover on wlan controller materials collected
24
2
critical analysis on research papers on roaming
8
11/16/2013
11/16/2013
11/16/2013
11/16/2013
literature review notes on handsoff/ handover made
25
1
research papers gathered to study codec in Voip
6
11/17/2013
11/17/2013
11/17/2013
11/17/2013
materials for voip codec collected
26
2
more analysis on Wlan architecture
5
11/17/2013
11/17/2013
11/17/2013
11/17/2013
Critique notes on Wlan architecture
27
1
More research on codec used in voice over internet protocol.
10
11/18/2013
11/18/2013
11/18/2013
11/18/2013
recommendation for voip codec made
28
1,2
supervisory session with supervisor for guidance on literature review
3
11/19/2013
11/19/2013
11/19/2013
11/19/2013
literature review amendment from supervisor
29
1
6
11/19/2013
11/19/2013
11/19/2013
11/19/2013
Guaranteed QoS investigation done.
30
1,2,7
more research on VOIP Protocols
present draft for literature review and consult supervisor to review
draft
8
11/20/2013
11/20/2013
11/20/2013
11/20/2013
supervisory review updates
31
1,2,7
prepare an updated reviewed literature after correction from supervisor
8
11/21/2013
11/21/2013
11/21/2013
reviewed draft for literature review corrected
32
3
supervisory briefing with supervisor as regards to designing prototype
3
11/22/2013
11/22/2013
11/22/2013
concept for prototype design discussed and finalized
33
1,2
8
11/23/2013
11/24/2013
11/24/2013
literature review documents is made available for next review
final touch on literature review
34
Practical phase
11/21/2013
11/22/2013
11/23/2013
167
METHODOLOGY PHASE COMPLETE
35
3
Analyzing various stage for designing and building VoWlan prototype
10
11/25/2013
10/27/2013
11/25/2013
10/27/2013
design and build of prototype preparation phase done
36
3
12
11/27/2013
11/28/2013
11/27/2013
11/28/2013
Gathering, learning and discovering tools for setup of VoWLAN
37
3
Acquiring tools needed for setting up VoWLAN prototype
Session briefing with client to discuss prototype network to be
implemented
1
11/29/2013
11/29/2013
11/29/2013
11/29/2013
Client Network design understand and building initiation up next
38
3,4
configuring 3cx server
14
11/30/2013
11/30/2013
11/30/2013
11/30/2013
configuration of 3cx VoIp server done
39
3
implementing call functionalities on server
7
12/1/2013
12/2/2013
12/1/2013
12/2/2013
implementation of call features done
40
3
14
12/3/2013
12/5/2013
12/3/2013
12/5/2013
Wlan setup done with router functions
41
3
Setting up WLAN NETWORK
configuration for setting up wireless controlller and access point for
secure Wlan
14
12/5/2013
12/7/2013
12/5/2013
12/7/2013
Wlan configuration to setup wireless controller and access point
42
3
integrating 3CX system on WLAN
14
12/7/2013
12/9/2013
12/7/2013
12/9/2013
access basic call on wlan done
43
4
testing call roaming and routing functionality of WLAN
8
12/9/2013
12/10/2013
12/10/2013
12/10/2013
carrying basic operational features on a WLAN done
101
44
4
Testing functions of configured 3cx server
8
12/12/2013
12/13/2013
12/12/2013
12/13/2013
other functionalities carried out through the 3cx server
45
4
configuring 3cx soft phones
5
12/14/2013
12/16/2013
12/14/2013
12/16/2013
soft phones configured
46
4
Discussion with supervisor to review implementation phase
12
12/18/2013
12/19/2013
12/18/2013
12/19/2013
supervisory session done and QoS implementation carried out
47
5
12
12/20/2013
12/22/2013
12/20/2013
12/22/2013
methodology chapter done and awaiting review
48
5
14
12/21/2013
12/25/2013
12/21/2013
12/25/2013
evaluation on project verified and matched to client requirement
49
5
drafting out methodology/ practical chapter
analysis and evaluation by testing the prototype VoWLAN to match TOR
objectives
Results evaluations of mos tests and provide recommendation for
future work (questionnaire)
12
12/28/2013
12/29/2013
12/28/2013
12/29/2013
checklist of sponsor ticked with prototype objectives fulfilled
50
3,4,5
5
12/30/2013
12/30/2013
12/30/2013
12/30/2013
demonstration feedback received from client/supervisor
51
3,4,5
preparation for demonstration to exhibit prototype functions for client
feedback review from demonstration and consideration for future
research
5
12/31/2013
12/31/2013
12/31/2013
12/31/2013
recommendation enhancement in line with feedback done
52
Dissertation and analysis stage
125
Dissertation stage complete
53
6
preparation and assembling outline for dissertation
16
1/2/2014
1/3/2014
1/2/2014
1/3/2014
structured outline drafted for dissertation
54
6
Compiling dissertation draft
18
1/2/2014
1/5/2014
1/2/2014
1/5/2014
dissertation draft compiled
55
6
Assess dissertation draft to match objectives on TOR
16
1/6/2014
1/7/2014
1/6/2014
1/7/2014
dissertation draft matched TOR
56
6
supervisory session to discuss dissertation draft
3
1/8/2014
1/8/2014
1/8/2014
1/8/2014
Feedback of dissertation draft done
58
6
compilation of final dissertation
18
1/10/2014
1/10/2014
1/10/2014
1/10/2014
produced final documentation for dissertation
59
7
dissertation assessment by clients
10
1/11/2014
1/11/2014
1/11/2014
1/11/2014
assessment finalized by client on dissertation
60
1,2,3,4,5,6,7
feedback on the project
10
1/11/2014
1/12/2014
1/11/2014
1/12/2014
feedback from client reviewed
61
1,2,3,4,5,6,7
amend project as regards to clients feedback
14
1/12/2014
1/15/2014
1/12/2014
1/15/2014
client feedback updated on dissertation
62
7
formatting, proofreading , printing and binding
14
1/17/2014
1/18/2014
1/17/2014
1/18/2014
produced copy of project
49
1,2,3,4,5,6,7
project final hand in
6
1/20/2014
1/20/2014
1/20/2014
1/20/2014
project submitted
50
Total Hours
600
KEY DATES
ST
1 review dissertation Planning assessment
11/7/2013
11/7/2013
Project Hand-in
1/20/2014
1/20/2014
VIVA
1/23/2014
1/23/2014
102
Section 2.2 ethical, Social, legal, professional and regulatory issues
Project Title: Evaluating VoIP performance over WLAN for Average Business
Client:
Location of client: Sunderland (United Kingdom)
Description
Social
impact
issues
Ethical
issues
The sponsor intends deploying Voice over Internet Protocol (VoIP) solution on
their already existing network. The sponsor is aware that voice can be
transmitted over data networks and wants it on a wireless local area network to
support call mobility within the office premises. However, the sponsor is aware
that a prim analysis is necessary to ensure mobility of call in the WLan because of
different WLan issues.
The sponsor’s VoIP set-up will be fabricated as a prototype and will be tested to
see if the prototype is capable of roaming voice within the sponsor’s premises.
The built prototype and sponsors VoIP infrastructure will be alike, so they may be
possibilities of unavailability of the VoIP system or inability to roam, However,
issues of call security may arise and may tell on the sponsor’s privacy.
The law of computer ethics can be seen in the below link.
http://computerethicsinstitute.org/images/TheTenCommandmentsOfComputerE
thics.pdf
103
Evaluation of
impact/risk
High
The sponsor
is conscious
of time
constrain to
totally
analyse all
the criterion
that will
guarantee
call quality
within
VoWLAN and
will want the
scope to be
narrowed
down to
testing
roaming for
call mobility
in the
network
Low
Since it’s a
simulation to
be carried
out that is
modelled to
the designed
prototype for
sponsor’s
VoIP system.
So, Therefore
there
shouldn’t be
worries for
Profession
al issues
It is a chance to improve knowledge, skill and technical ability in VoIP over Wlan.
There is need to be careful with the methods I will be using, and also carefully
employing the correct laboratory tools, to enable proper analysis to be carried
out and avoid delay and other concerns in Vowlan.
Legal
Issues
Every nation has it legal regulatory issues; However, in the UK the legal system
allows the law of competition to define important national markets.
http://www.legislation.gov.uk/ukpga/2003/21/section/125
the
sponsoring
organization
High impact
Increases
know how
personal skill
set that will
be for
marketable
purposes
LOW
There may be
further
changes to
the
legislation.
Section 2.4 Plan for evaluating success of project
Objective
How will project success be evaluated
1. To research features of VoIP over WLAN
relevant to deliver communication needs in old
people’s home.
A critical research on features in VoWLAN
needed in old people’s home using peer
reviewed literatures.
Evidence: Good critiquing and worthy argument
on literature review grounded on the
characteristics and features VoIP brings to old
people’s home businesses
2. To research properly on roaming in WLAN
access points with QoS
Critical review of Peer reviewed article
literatures on WLAN architecture, component,
handover/roaming, VoIP architecture,
component and QoS
Evidence: Good analysis on reviewed literatures
and well critiqued explanation of WLAN
architectures, roaming principles and QoS for
VoIP
104
3. Design and implementation of a roaming
prototype VoIP system over WLAN using 3CX
A Designed and implemented prototype VoIP
System on WLAN based on the Sponsor’s VoIP
Network system.
Evidence:
A properly defined Topology of prototype VoIP
system over WLAN network with the different
tools for setup.
Integrating VoIP on the WLAN, well explained
methods of describing Association of Voice on
802.11 network using 3CX for call and data to
exist in network will be simulated in the
laboratory with physical equipment
4 Test prototype for roaming and Voice quality
and operability
Carrying out testing of the designed and
implemented VoIP system over the WLAN for
roaming
Evidence:
Laboratory experiment will be Simulated with
the VoIP soft phones on the wireless LAN.
Mobility of calls within the access points area is
the test case, and assumption of Voice quality.
The Mean Opinion Score method will be used to
test the implemented VoIP network Prototype
for Roaming, Voice Quality and Operability.
5 evaluate prototype on best industry standards
Analysis of results obtained from roaming test.
Evidence:
Output data analysis from roaming MOS TEST
with graphical illustration and diagrams and
report on test
6 Give recommendation for future improvement
Recommend future techniques to guarantee
roaming in a WLAN for voice and analyse
potential areas of research that will be profitable
to this project
Evidence:
Enhanced VoWLAN design with recommended
Roaming technique and highlights of further
research areas to that improves roaming for
voice in wlan for better QoS
Proper Critiquing, analysis and evaluations of
project.
Evidence:
An Electronic copy and hard copy of the written
dissertation with respect to project
7 To Present dissertation
105
APPENDIX B
Client Feedback form
106
107
108
109
SUPERVISORY FORM SHEET
110
111
112
113
114
115
116
117
118
119
120
121
122
123
Sickness forms
124
125
MOS SHEET
126
127
128
129
130
131
132
133
134
135
136
137
Appendix C
THE LAYER3 SWITCH Configuration
en
conf t
ip routing
hostname Malone
vlan 2
name management
exit
vlan 3
name malonecarevoice
exit
vlan 4
name malonedatacare
exit
ip dhcp excluded-address-
ip dhcp excluded-address-
ip dhcp excluded-address-
ip dhcp pool LWAP
network-
default-router-
Option 43 hex f104c0a80203
Exit
ip dhcp pool malonecarevoice
network-
default-router-
exit
ip dhcp pool malonedatacare
network-
default-router-
exit
interface FA0/2
NO SWITCHPORT
ip address-
no shutdown
exit
interface FA0/3
NO SWITCHPORT
ip address-
no shutdown
exit
interface Vlan2
ip address-
138
exit
interface Vlan3
ip address-
exit
interface Vlan4
ip address-
exit
int fa0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 2,3,4
switchport mode trunk
mls qos trust cos
no shutdown
exit
Layer2 switch
en
conf t
hostname maloneswitch
vlan 6
name LWAP
exit
vlan 7
name WIRED
exit
int range fa0/1-12
switchport mode access
switchport access Vlan 6
mls qos trust dscp
exit
int range fa0/13-24
switchport mode access
switchport access vlan 7
mls qos trust dscp
exit
monitor session 1 source int fa0/1- 23
monitor session 1 destination int fa0/24
139
WLC CONFIGURATION
G1WLC1
CISCO
CISCO-
Group1
Malonenetwork
YES
YES-
Apple
GB
YES
YES
YES
YES
CISCO
CISCO
CONFIG PROMPT G1WLC1
CONFIG NETWORK TELNET ENABLE
CONFIG NETWORK WEBMODE ENABLE
SAVE CONFIG
YES
140
3CX PHONE SYSTEM CONFIGURATION
CALL CONFERENCE CONFIGURATION
CALL RECORDING CONFIGURATION
141
CONFIGURING EXTENSION ON PBX
CONFIGURING AUTO-ATTENDANCE
142
Configuring Group RING
CONFIGURING Voicemail for EXTENSION
143
Configuring Call queue
144
