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.
Descrição
Used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP.
Quando você o vê
During call setup, especially in PSTN interworking scenarios. The response may contain SDP for early media like custom ringback tones or IVR prompts.
Como corrigir
No fix needed — this is informational. If early media is not playing, check codec negotiation and SDP handling in your UA.
Descrição
The address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint.
Quando você o vê
When a user has multiple registered devices or contact addresses and the server cannot determine which one to use.
Como corrigir
Select one of the provided Contact addresses and resend the request to that specific URI.
Diferenças principais
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.
Quando usar qual
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.