SIP 定时器 总结

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SIP 定时器的总结 定时器 缺省值 节 含义

T1	500 ms	17.1.1.1	经历来回时间（RTT）
T2	4 秒	17.1.2.2	非 INVITE 请求和 INVITE 响应的最长重新传输时间间隔
T4	5 秒	17.1.2.2	消息可保留在网络中的最长持续时间
计时器 A	最初为 T1	17.1.1.2	INVITE 请求重新传输时间间隔（仅适用于 UDP）
计时器 B	64*T1	17.1.1.2	INVITE 事务超时计时器
计时器 D	大于 32 秒（对于 UDP）	17.1.1.2	响应重新传输的等待时间
0 秒（对于 TCP 和 SCTP）
计时器 E	最初为 T1	17.1.2.2	非 INVITE 请求重新传输时间间隔（仅适用于 UDP）
计时器 F	64*T1	17.1.2.2	非 INVITE 事务超时计时器
计时器 G	最初为 T1	17.2.1	INVITE 响应重新传输时间间隔
计时器 H	64*T1	17.2.1	ACK 接收的等待时间
计时器 I	T4（对于 UDP）	17.2.1	ACK 重新传输的等待时间
0 秒（对于 TCP 和 SCTP）
计时器 J	64*T1（对于 UDP）	17.2.2	重新传输非 INVITE 请求的等待时间
0 秒（对于 TCP 和 SCTP）
计时器 K	T4（对于 UDP）	17.1.2.2	响应重新传输的等待时间
0 秒（对于 TCP 和 SCTP）

计时器 k :

RFC 3261 - 17.1.2.2

If Timer K fires while in this state (Completed), the client transaction
MUST transition to the "Terminated" state.

RFC 3261 - 17.1.2.2
ONCE THE TRANSACTION IS IN THE TERMINATED STATE, IT MUST BE DESTROYED IMMEDIATELY.

计时器 L ：

draft-sparks-sip-invfix-03 - 8.7. Page 137
If Timer L fires while the INVITE server transaction is in the "Accepted" state, the transaction
MUST transition to the "Terminated" state. Once the transaction is in the "Terminated" state, it MUST be
destroyed immediately.

计时器 L触发时会结束 IST事务。

计时器 I

RFC 3261 - 17.2.1 INVITE Server Transaction
Once timer I fires, the server MUST transition to the
"Terminated" state.


Once the transaction is in the "Terminated" state, it MUST be
destroyed immediately. As with client transactions, this is needed
to ensure reliability of the 2xx responses to INVITE.

计时器 D：

draft-sparks-sip-invfix-03 - 8.4. Pages 126 through 128
If timer D fires while the client transaction is in the
"Completed" state, the client transaction MUST move to the
"Terminated" state.

计时器 M：

draft-sparks-sip-invfix-03 - 8.4. Pages 126 through 128
If timer M fires while the client transaction is in the "Accepted"
state, the client transaction MUST move to the "Terminated" state.

计时器 F：

RFC 3261 - 17.1.2.2
If timer F fires while in the "Proceeding" state, the TU MUST be informed of a timeout, and the
client transaction MUST transition to the terminated state.

计时器 J ：

RFC 3261 - 17.2.2
The server transaction remains in this state (Completed) until Timer J fires, at
which point it MUST transition to the "Terminated" state.

RFC 3261 - 17.2.2
THE SERVER TRANSACTION MUST BE DESTROYED THE INSTANT IT ENTERS THE "TERMINATED" STATE.