SIP 300 Multiple Choices vs 480 Temporarily Unavailable
SIP 300 (Multiple Choices) is a 3xx Redirection response, while 480 (Temporarily Unavailable) is a 4xx Client Failure response. 300 indicates that the address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint. 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 address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint.
Cuándo lo verás
When a user has multiple registered devices or contact addresses and the server cannot determine which one to use.
Cómo solucionarlo
Select one of the provided Contact addresses and resend the request to that specific URI.
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
300 is a 3xx Redirection response, while 480 is a 4xx Client Failure response.
SIP 300: The address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint.
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 300 when when a user has multiple registered devices or contact addresses and the server cannot determine which one to use.
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 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI. 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.