POLYTECHNIC OF NAMIBIA SCHOOL OF INFORMATION TECHNOLOGY DEPARTMENT OF SOFTWARE ENGINEERING TITLE: Research and Development of a mobile voice over IP application which is hosted by open source software running on inexpensive backend servers Thesis presented in partial fulfilment of the requirements for the degree of Master of Information Technology at the Polytechnic of Namibia. Presented by: Veiko Muronga (9864431) Supervisor: Prof. Hippolyte Nsung-Nza Muyingi Second Supervisor: None. March 2013 DECLARATION I, Veiko Mpareke Muronga, hereby declare that the work contained in the mini–thesis, entitled: ”Research and Development of a mobile voice over IP application which is hosted by open source software running on inexpensive backend servers”, is my own original work and that I have not previously in its entirety or in part submitted it at any University or other higher education institution for the award of a degree. Signature:……………………….. Date:………………………….. RETENTION AND USE OF THESIS I, Veiko Mpareke Muronga, being a candidate for the degree of Master of Information Technology accepts the requirements of the Polytechnic relating to the retention and use of Master’s theses/ mini-theses deposited in the Library. In terms of these conditions, I agree that the original of my thesis/mini-thesis deposited in the Library will be accessible for purpose of study and research, in accordance with the normal conditions established by the Librarian for the care, loan or reproduction of theses/mini-theses. Signature:……………………….. Date:………………………….. 2 ABSTRACT Voice over IP has been driven by the convergence of voice and data on a single transport medium. This means cheaper service usage fees for the user if the offering is costed properly. But for a service provider there is still an increase in expenditure, solely related to spending on infrastructure such as call servers, phones and gateways. This study is aimed at analysing a different strategy of deploying VoIP, by starting at a lower base, meaning hosting the VoIP application on inexpensive hardware and open source Software. Secondly, the study looks at how to extend the service to mobile subscriber by introducing a mobile VoIP (mVoIP) application. The study’s main goal is to introduce telecommunication services at the lowest cost possible while considering reduced complexity, optimisation, manageability and flexibility. Barriers to deploying VoIP such as reliability and quality of service are also addressed by the study. The mVoIP infrastructure is made out of the following main components: Mobile VoIP app, Wireless Access Point and VoIP Server. Each main component’s functionality and characteristic are carefully explored in order to understand its contribution to the solution and the study as a whole. The research also looks at other projects where similar approaches were used to deploy inexpensive VoIP services. Factors leading to acceptance or rejection of the technology have served as guidance to the study. During the design, the research compares different open source VoIP server software’s functionalities and features in order to make a selection of the software to use for the projects pilot network deployment. A development platform for the mobile application is also selected based on characteristics such as: the range of devices it runs on, the market share of the platform and the learning curve of the platform. The development of the application follows the six steps from the Eri Mobile’s “Mobile Development Process”: Concept Sketching, Research/Strategies, Wire-Framing, User Interface Design, Development and Testing. The test scenarios for the research are all lab-based, but it is highlighted that implementing the solution on broadband, 3G and 4G networks can improve the service drastically in the areas of network coverage, Quality of Service and Mobility. 3 ACKNOWLEDGEMENT As anyone who has undertaken the task of writing knows that writing a thesis is a difficult and time consuming effort. Therefore my first acknowledgement must be to my wife Abigahil and son Mika who spend their nights alone, while I was writing this thesis. Secondly, I would like to thank my supervisor Prof. H.N. Muyingi for his valuable inputs and constant support and guidance during this whole journey. And to my parents (Mr. Mika Muronga and Mrs. Renate Muronga), I would like to give a big thank you for always being there for me in everything that I have tried. To the rest of my family and friends, thanks for your patience and support during my studies and I promise that soon we will get back on track to execute all our plans. Last but most importantly I would like to say thanks to the Mighty Father GOD for giving me the strength and endurance through my studies and beyond. 4 Table of Contents Declaration .......................................................................................................................................... 2 Retention and Use of Thesis ............................................................................................................... 2 Abstract ............................................................................................................................................... 3 Acknowledgement .............................................................................................................................. 4 List of Acronyms ................................................................................................................................ 9 List of Figures ................................................................................................................................... 13 List of Tables .................................................................................................................................... 15 1. INTRODUCTION .................................................................................................................... 16 1.1. Definition of the Problem ..................................................................................................... 16 1.2. Motivation ............................................................................................................................. 16 1.3. Scope ..................................................................................................................................... 18 1.4. Project Objectives – Deliverables ......................................................................................... 19 1.5. Definition of Terms ................................................................................................................... 20 1.5.1. Core Network Terminology .......................................................................................... 20 1.5.2. Transport Network Terms ............................................................................................. 21 1.5.3. Access Network Terms ................................................................................................. 21 1.5.4. Security Terms .............................................................................................................. 23 1.5.5. Protocols ....................................................................................................................... 24 1.5.6. Standards ....................................................................................................................... 25 1.5.7. Other Terms .................................................................................................................. 26 1.6. Hypothesis and Research Questions to be investigated ............................................................ 26 1.7. Thesis Structure .................................................................................................................... 27 1.8. Summary ............................................................................................................................... 28 2. LITERATURE REVIEW ......................................................................................................... 29 2.1. Introduction ........................................................................................................................... 29 2.2. Voice over IP ........................................................................................................................ 29 2.2.1. Requirements of a VoIP Network ................................................................................. 31 5 2.2.2. Protocols Related To VoIP ........................................................................................... 33 2.2.3. SIP Architectural Components ...................................................................................... 44 2.2.4. SIP Messages ................................................................................................................ 45 2.2.5. SIP Transactions ........................................................................................................... 48 2.2.6. Conclusion .................................................................................................................... 50 2.3. Adoption Factors of VoIP ..................................................................................................... 50 2.4. Mobile VoIP .......................................................................................................................... 52 2.5. IEEE 802.11 Architecture ....................................................................................................