SIP 300 Multiple Choices vs 439 First Hop Lacks Outbound Support
SIP 300 (Multiple Choices) is a 3xx Redirection response, while 439 (First Hop Lacks Outbound Support) 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, 439 means that the first outbound proxy does not support the SIP outbound mechanism (RFC 5626) that the UA is trying to use.
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 first outbound proxy does not support the SIP outbound mechanism (RFC 5626) that the UA is trying to use.
Cuándo lo verás
When a UA configured for SIP outbound connects to a proxy that doesn't support the outbound option-tag.
Cómo solucionarlo
Upgrade the outbound proxy to support RFC 5626, or configure the UA to not require outbound support.
Diferencias clave
300 is a 3xx Redirection response, while 439 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 439: The first outbound proxy does not support the SIP outbound mechanism (RFC 5626) that the UA is trying to use.
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 439 when when a UA configured for SIP outbound connects to a proxy that doesn't support the outbound option-tag.
Cuándo usar cada uno
For 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI. For 439 (First Hop Lacks Outbound Support): Upgrade the outbound proxy to support RFC 5626, or configure the UA to not require outbound support.