Design, Modeling and simulating an IP based Public Voice Network Topology

Abstract

Voice over the TDM based PSTN has been the main source of communication for the public over decades. With the rapid development of the Internet Protocol and its applications, voice transmission over IP networks has become popular. A technology so called Voice over IP (VoIP) has been evolved to facilitate such services. It is predicted that, in the future the conventional PSTN system will gradually be replaced with an IP based converged network which will carry both data and the voice. Users will have a single access line to the network for accessing the data and voice. Developed countries have taken steps in advance in terms of technology, standards and policy to take the full benefits of the IP convergence in public networks. This project has identified the need of such an IP based public converged network for Sri Lanka to cater her burning need of communication infrastructure development.

This report is a part of the individual project based on the design and modeling of a public IP based voice network topology for Sri Lanka. The aim of this report is mainly to discuss the project background, requirement analysis and to propose a design for the VoIP infrastructure in Sri Lanka. Efforts were focused in identifying the weaknesses in current telecommunication infrastructure in Sri Lanka and the reasons as to why we are migrating to an IP network. Primary issues that are associated with and must be addressed in designing a large scale VoIP network that is capable of supporting full PSTN equivalence also were taken into consideration.

Theories behind the IP Convergence and the technologies that are used to implement a public IP network are also be discussed in brief. Proposed infrastructure section will discuss the possible challenges that has to be over come in proposing a converged solution. The proposed solution and the implementation of the test setup to model the proposed solution has been described in detail. Measurements and evaluations that have to be done on the test setup, based on which estimations in terms of device capacity and scalability are also discussed. Efforts are focused in designing a topology which is technically feasible and scalable. Quality of Service in VoIP was focused in a similar project carried out by Mr. Nadesu Yogeswaran under the supervision of Dr. Nalin Ranasinghe of UCSC.

The objective of the project is to propose a design and a model for an IP network which will gradually replace the existing PSTN network and deliver the services equivalent to PSTN in terms of quality and reliability. This dissertation report is an attempt to demonstrate the efforts made to achieve the above objectives.