SIP 302 Moved Temporarily vs 423 Interval Too Brief
SIP 302 (Moved Temporarily) is a 3xx Redirection response, while 423 (Interval Too Brief) 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, 423 means that the expiration time in the request is too short. The response contains a Min-Expires header indicating the minimum allowed value.
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 expiration time in the request is too short. The response contains a Min-Expires header indicating the minimum allowed value.
When You See It
When a REGISTER or SUBSCRIBE request has an Expires value that is below the server's minimum. Common with aggressive keep-alive timers.
How to Fix
Increase the Expires header value to at least the Min-Expires value from the response.
Key Differences
302 is a 3xx Redirection response, while 423 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 423: The expiration time in the request is too short. The response contains a Min-Expires header indicating the minimum allowed value.
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 423 when when a REGISTER or SUBSCRIBE request has an Expires value that is below the server's minimum. Common with aggressive keep-alive timers.
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 423 (Interval Too Brief): Increase the Expires header value to at least the Min-Expires value from the response.