Research of setting up Session Initiation Protocol based VoIP system

[[abstract]]This paper presents a research of setting up a SIP-based (Session Initiation Protocol) VoIP(Voice over IP) system environment. A complete SIP-based VoIP system can be separated into two parts. The first is a SIP-based UA(User Agent) for client to use, the second is a SIP-based server system that can provide SIP message service. The research of this paper is based on using licensed share open source code, with modifying and compiling to set up a server system that can support SIP message service. After setting up a complete server system, any user in this system can create a session with SIP to transmit multimedia streaming data. In order to verify the functionality of our SIP system and make sure that it can support standard SIPv2 message flow. We used other SIP-based client program open source that support SIPv2 form different develop group to connect with our server system. We must make sure that the UA can register, invite, and connect… with our SIP server. Because we used a standard SIPv2 server system, no matter what programming language the UA used, as long as it can tally with SIPv2 message, we can use this UA to register in our server database and invite any other user in the same system to initiate a session. The benefit of setting up a SIP server is to create an independent communication environment. It can support the development of SIP programming in our lab, and the research about the multimedia applications.