SIP 300 Multiple Choices vs 481 Call/Transaction Does Not Exist
SIP 300 (Multiple Choices) is a 3xx Redirection response, while 481 (Call/Transaction Does Not Exist) 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, 481 means that the UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
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 UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
Cuándo lo verás
When sending a BYE, re-INVITE, or UPDATE for a call that the server has no record of. Common after server restarts.
Cómo solucionarlo
The dialog has been lost. Terminate the local call state. For re-INVITE failures, re-establish the call from scratch.
Diferencias clave
300 is a 3xx Redirection response, while 481 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 481: The UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
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 481 when when sending a BYE, re-INVITE, or UPDATE for a call that the server has no record of. Common after server restarts.
Cuándo usar cada uno
For 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI. For 481 (Call/Transaction Does Not Exist): The dialog has been lost. Terminate the local call state. For re-INVITE failures, re-establish the call from scratch.