SIP 183 Session Progress vs 200 OK
SIP 183 (Session Progress) is a 1xx Provisional response, while 200 (OK) is a 2xx Success 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, 200 means that the request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
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 request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
Quando você o vê
When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
Como corrigir
No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.
Diferenças principais
183 is a 1xx Provisional response, while 200 is a 2xx Success 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 200: The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
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 200 when when a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
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 200 (OK): No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.