Design And Implementation Of A Network Intercom System Based On JAVA

Followed with network developing fast and network users increasing remarkably, VoIP technology is also developed day by day. VoIP contains two key protocols:H.323 protocol and SIP protocol. Compared with H.323 protocol which is defined earlier and used broadly, the emerging SIP protocol has more merits, such as implementation simple, modification easy, text based, application range broad and supporting interface diversified.Since the IETF proposed the SIP protocol, SIP has developped based on the Internet and now has been widely used, but still limited to a single point of communication application. However, the nature flexibility and expansion of SIP makes it a good combination with the NGN network and become the most important NGN session control protocol. If enterprise network wants to communicate with SIP protocol in NGN network, it needs to deal with voice signal which guarantees the quality of voice transmission and control signaling which is responsible for the session establishment between SIP protocol and the enterprise internal network.Based on the company commissioned project----design and implementation of network intercom system, this project aims to implement the function of soft phone and server which are based on the network. We use SIP protocol to control signaling and use JMF to implement the voice processing.The system contains two main models:the design and implementation of the soft phone;the design and implementation of the server.At the beginning,this article studies some key technologies such as SIP protocol, SDP, JMF and RTP. Taking use of SIP protocol stack and JMF, we develop the user agent and implemente the voice processing. In the end, according to the business requirements, we design the user server which can control the end users. With the modular design and the develop tool of java,we implement the SIP user agent soft phone terminal with call connection,removal,voice communication function and so on. We also implemente the server which supports forwarding routing, on-line query multicast communication and other functions.