SIP 180 Ringing vs 302 Moved Temporarily
SIP 180 (Ringing) is a 1xx Provisional response, while 302 (Moved Temporarily) is a 3xx Redirection 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, 302 means that the callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future requests.
Description
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.
When You See It
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
How to Fix
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.
Description
The callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future requests.
When You See It
When a user is temporarily reachable at a different location, such as when traveling or using a different device.
How to Fix
Redirect the current call to the Contact URI provided, but keep the original URI for future requests.
Key Differences
180 is a 1xx Provisional response, while 302 is a 3xx Redirection response.
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.
SIP 302: The callee has temporarily moved to a different address. The client should retry the request at the Contact address but continue using the original URI for future requests.
You encounter 180 when during call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
You encounter 302 when when a user is temporarily reachable at a different location, such as when traveling or using a different device.
When to Use Which
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 302 (Moved Temporarily): Redirect the current call to the Contact URI provided, but keep the original URI for future requests.