SIP 183 Session Progress vs 502 Bad Gateway
SIP 183 (Session Progress) is a 1xx Provisional response, while 502 (Bad Gateway) is a 5xx Server Failure 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, 502 means that the server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
Mô tả
Used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP.
Khi bạn thấy mã này
During call setup, especially in PSTN interworking scenarios. The response may contain SDP for early media like custom ringback tones or IVR prompts.
Cách khắc phục
No fix needed — this is informational. If early media is not playing, check codec negotiation and SDP handling in your UA.
Mô tả
The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
Khi bạn thấy mã này
When a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
Cách khắc phục
Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.
Sự khác biệt chính
183 is a 1xx Provisional response, while 502 is a 5xx Server Failure 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 502: The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
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 502 when when a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
Khi nào dùng cái nào
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 502 (Bad Gateway): Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.