The Study Of SIP Simulation Method Based On NS2

SIP, the Session Initiation Protocol, is developed within the IETF working group, and is an instant communication application signaling protocol based on IP networks. SIP is the core protocol of NGN (Next Generation Network) and is intended to deal with the signaling control on IP network. The final goal of SIP is to provide ubiquitous Internet access and to become the media connecting Internet, multimedia and telecommunication.In the course of the studying the new technologies, it is hard to build the actual network system. So, simulation is one of the best ways to test, evaluate and verify the network system under this circumstance. The cycle of network simulation is short, and the cost of simulation is low. Other researchers can take advantage of the existing results and can pay more attention to their own studies.Under this background, the thesis analyzes a SIP system scheme systemically based on some foreign and domestic references and existing NS2 components. The scheme will make the development of a SIP system easier.The emphasis of the thesis is the design and realization of SIP packet header, UAAgent, ProxyAgent, RedirectAgent, DNSAgent, retransmission Timer and SIP Application on NS2. The processes of SIP system designed in this thesis include the registering of UA and Proxy Server, the communication between UAs using Proxy Server inside a domain and among domains, and the communication between UAs using Redirect Server. Then the system is tested with OTcl scripts.Last, further research directions are pointed out at the end.