SIP 302 Moved Temporarily vs 480 Temporarily Unavailable
SIP 302 (Moved Temporarily) is a 3xx Redirection response, while 480 (Temporarily Unavailable) is a 4xx Client Failure response. 302 indicates 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. In contrast, 480 means that the callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
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.
Description
The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
When You See It
When the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
How to Fix
Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.
Key Differences
302 is a 3xx Redirection response, while 480 is a 4xx Client Failure response.
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.
SIP 480: The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
You encounter 302 when when a user is temporarily reachable at a different location, such as when traveling or using a different device.
You encounter 480 when when the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
When to Use Which
For 302 (Moved Temporarily): Redirect the current call to the Contact URI provided, but keep the original URI for future requests. For 480 (Temporarily Unavailable): Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.