SIP

SIP 180 Ringing vs 482 Loop Detected

SIP 180 (Ringing) is a 1xx Provisional response, while 482 (Loop Detected) is a 4xx Client Failure response. 180 indicates that the UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end. In contrast, 482 means that the server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

Beschreibung

The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.

Wann Sie es sehen

During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.

Wie man es behebt

No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings.

Beschreibung

The server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

Wann Sie es sehen

When routing configuration causes a request to cycle between two or more proxies without reaching the callee.

Wie man es behebt

Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.

Wesentliche Unterschiede

1.

180 is a 1xx Provisional response, while 482 is a 4xx Client Failure response.

2.

SIP 180: The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.

3.

SIP 482: The server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

4.

You encounter 180 when during call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.

5.

You encounter 482 when when routing configuration causes a request to cycle between two or more proxies without reaching the callee.

Wann welchen verwenden

For 180 (Ringing): No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings. For 482 (Loop Detected): Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.

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