SIP呼叫典型流程图解及详细解释
目录
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.
Sip协议的相关术语: ............................................................................................................ 2 注册流程 ................................................................................................................................... 4 注销流程: ............................................................................................................................... 6 基本呼叫建立过程: ............................................................................................................... 7 会话更改流程: ....................................................................................................................... 9 正常呼叫释放过程: ............................................................................................................. 12 被叫忙呼叫释放: ................................................................................................................. 13 被叫无应答流程一: ............................................................................................................. 14 被叫无应答流程二: ............................................................................................................. 15 遇忙呼叫前转: ................................................................................................................. 16 无应答呼叫前转流程: ..................................................................................................... 18 呼叫保持: ......................................................................................................................... 20 呼叫等待: ......................................................................................................................... 23 盲转流程 ............................................................................................................................. 27 询问转的流程 ..................................................................................................................... 30 彩铃的流程 ......................................................................................................................... 31 三方通话 ............................................................................................................................. 34
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1. Sip协议的相关术语:
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A拨打B,A到proxy是一个session,一个dialog,proxy到b是另一个dialog,有另一个session name。
Invite,ack,bye,option,update,cancel消息,每发一个就是一个事务。每发一个请求,cseq加1,但cancel,ack,bye请求的cseq同invite的cseq。Callid,from tag,to tag标识一次对话。Invite消息中有from tag,没有to tag,100 trying应答也没有to tag。被叫发的bye中from,to的tag和180和200ok的值。
每个事务用via字段里的branch的值来区分,invite到200ok之间属于一个事务,bye是另一事务。
语音流,被叫收到ack后发一个rtp流。
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