摘要
由IETF的MMUSIC工作组提出的会话初始协议(SIP)采用与H.323不同的设计理念来实现Internet多媒体通信的信令功能,它借鉴了其它Internet的标准和协议的设计思想,坚持简练、开放、兼容和可扩展等原则,在复杂性、可扩展性以及呼叫建立过程等方面都优于H.323。SIP主要采用三种呼叫方式建立连接:直接呼叫、重定向呼叫和代理呼叫。
SIP,raised by MMUSIC working group of IETF,adopts design idea different from H.323to realize the signaling function of multi -media communication on Internet.It use for reference the design ideas of other Internet stan dards and protocols,sticking to the principle of concise,open,compatible and extendable.It is superior to H.323in complexity,extendibility and call establish ing process.SIP mainly adopts3ty pes of call ing modes to establish connection:direct call,re-di rect call and agent call.
出处
《世界电信》
2002年第10期45-48,共4页
World Telecommunications
