SIP 301 Moved Permanently vs 480 Temporarily Unavailable
SIP 301 (Moved Permanently) is a 3xx Redirection response, while 480 (Temporarily Unavailable) is a 4xx Client Failure response. 301 indicates that the user can no longer be found at the address in the Request-URI. The client should direct future requests to the new address in the Contact header. 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.
Descripción
The user can no longer be found at the address in the Request-URI. The client should direct future requests to the new address in the Contact header.
Cuándo lo verás
When a user has permanently changed their SIP address. All future calls should be directed to the new URI.
Cómo solucionarlo
Update your address book or routing tables to use the new Contact URI provided in the response.
Descripción
The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
Cuándo lo verás
When the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
Cómo solucionarlo
Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.
Diferencias clave
301 is a 3xx Redirection response, while 480 is a 4xx Client Failure response.
SIP 301: The user can no longer be found at the address in the Request-URI. The client should direct future requests to the new address in the Contact header.
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 301 when when a user has permanently changed their SIP address. All future calls should be directed to the new URI.
You encounter 480 when when the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
Cuándo usar cada uno
For 301 (Moved Permanently): Update your address book or routing tables to use the new Contact URI provided in the response. 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.