SIP 300 Multiple Choices vs 503 Service Unavailable
SIP 300 (Multiple Choices) is a 3xx Redirection response, while 503 (Service Unavailable) is a 5xx Server 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, 503 means that the server is temporarily unable to process the request due to overloading or maintenance. The client should retry after the time indicated in the Retry-After header.
Описание
The address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint.
Когда вы это видите
When a user has multiple registered devices or contact addresses and the server cannot determine which one to use.
Как исправить
Select one of the provided Contact addresses and resend the request to that specific URI.
Описание
The server is temporarily unable to process the request due to overloading or maintenance. The client should retry after the time indicated in the Retry-After header.
Когда вы это видите
During server overload, maintenance windows, or when the server is rate-limiting requests. Common during traffic spikes.
Как исправить
Wait for the time specified in the Retry-After header. If persistent, check server capacity and consider load balancing across multiple SIP proxies.
Ключевые различия
300 is a 3xx Redirection response, while 503 is a 5xx Server 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 503: The server is temporarily unable to process the request due to overloading or maintenance. The client should retry after the time indicated in the Retry-After header.
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 503 when during server overload, maintenance windows, or when the server is rate-limiting requests. Common during traffic spikes.
Когда что использовать
For 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI. For 503 (Service Unavailable): Wait for the time specified in the Retry-After header. If persistent, check server capacity and consider load balancing across multiple SIP proxies.