SIP 183 Session Progress vs 300 Multiple Choices
SIP 183 (Session Progress) is a 1xx Provisional response, while 300 (Multiple Choices) is a 3xx Redirection response. 183 indicates that used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP. In contrast, 300 means 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.
Описание
Used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP.
Когда вы это видите
During call setup, especially in PSTN interworking scenarios. The response may contain SDP for early media like custom ringback tones or IVR prompts.
Как исправить
No fix needed — this is informational. If early media is not playing, check codec negotiation and SDP handling in your UA.
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.
Ключевые различия
183 is a 1xx Provisional response, while 300 is a 3xx Redirection response.
SIP 183: Used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP.
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.
You encounter 183 when during call setup, especially in PSTN interworking scenarios. The response may contain SDP for early media like custom ringback tones or IVR prompts.
You encounter 300 when when a user has multiple registered devices or contact addresses and the server cannot determine which one to use.
Когда что использовать
For 183 (Session Progress): No fix needed — this is informational. If early media is not playing, check codec negotiation and SDP handling in your UA. For 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI.