ABSTRACT

This dissertation mainly looked into all aspects of VoIP communications technology and information presented in preceding chapters, which build up a super frame work to discuss the conceptual design model and investigate features that could be incorporated for actual projects, with parameters that are tested on field values, the dissertation follows a five course model, for answering different questions, around central issues, that have been crucial to explanation of the topic; starting with a general overview of VoIP technology, analyzing current VoIP performance, identifiing security threats, pointing out the solutions to the problems affecting this technology. VoIP stands for voice over internet protocol. Unlike the traditional circuit-committed protocols of the public switched telephone network (PSTN), in VoIP voice signal is compressed and converted to digital voice packets, VoIP then uses the Internet Protocol (IP) for managing voice packets over IP network. Therefore, VoIP can be deployed on any IP enabled data network, such as the Internet, Ethernet, fabric or wireless network.

TABLE OF CONTENTS

DECLARATION .... ........~ ~ ii

DEDICATEON iii

ACKNOWLEDGEMENT ~ iv

TABLE OF CONTENTS ~

LIST OF ~ viii

LIST OF TABLES AND FIGURES ~

CHAPTER

INTRODUCTION 1 1.0. General Introduction 1

1.1 Background 2

1.2 Statement ofthe problem 2

1.3 Objectives 3

1.3.1 General objectives 3

1.3,2 Specific objectives 3

1.4 Research questions 3

1.5 Significance ofthe study 4

1.6 Scope ofthe study 4 1.7 Conceptual Framework s

CHAPTER TWO

LITERATURE REVIEW 7 2.0 Theoretical review 7

2.1. Review of related literature 8

2.1.1 Types of VoIP 8

2.1.2 Advantages for VOIP 9

2.1.3 Disadvantages for VOIP 10

2.3 VOIP System 11

2.3.1 Evolution towards PBX~~ljke VoIP 12

V

2.4 VoIP protocols .13

2.5 Corporate use 16

2.6 Reasons for VoIP Deployment 17

2.7 Security Measures 18

CHAPTER THREE~ ~

RESEARCH METHODOLOGY 20 3.0 Introduction 20

3.1 Data Collection instruments 20

3.2 Analysis, Design and Development of the prototype 20

3.3 Development methodology 21

3.4 Limitations of the Study 21

3.5 Conclusion 22

CHAPTER FOUR .. ......~.

DATA ANALYSIS AND FINDINGS 23 4.0 Introduction 23

4.1 Deductions from the Previous Chapter (Methodology) 23

4.2 General Observation 23

4.3 Modeling Assumptions 24

4.3.1 Scenario I: Impact of Increasing Number of VoIP Clients 25

4.3.2 Scenario 2: Impact of Wireless Nodes 25

4.3.3 Scenario 3: Impact of Voice Encoder Schemes 27

4.3.4 Scenario 4: Impact of Traffic Arrival Distributions 27

4.4 VoIP Traffic 28

4.5 VoIP traffic settings 30

4.5.1 VoIP application and profile settings 30

4.5.2 Configuration of voice action 30

4.6 VoIP Qo5 32

4.7 Solutions for VoIP security issues 34

4.8 Challenges of VoIP 37

4.9 Vulnerabilities 39

CHAPTER FWE 41

DISCUSSION, CONCLUSION AND RECOMMENDATIONS 41

vi

5.0 Introduction .41

5.1 Discussion41

5.2 Merit ofthe System 42

5.3 Limitations ofthe System 42

5.4 Problems Encountered 43

5.5 Conclusion 43

5.6 Recommendations 44

REFERENCES ...~..

APPENDICES..,, .

Appendix A:VOIP Risks, Threats, and Vulnerabilities 47 Appendix B: VOIP Frequently Asked Questions 55 Appendix C: VOIP Terms