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.
विवरण
Used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP.
जब आप इसे देखें
During call setup, especially in PSTN interworking scenarios. The response may contain SDP for early media like custom ringback tones or IVR prompts.
कैसे ठीक करें
No fix needed — this is informational. If early media is not playing, check codec negotiation and SDP handling in your UA.
विवरण
The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
जब आप इसे देखें
When a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
कैसे ठीक करें
Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.
मुख्य अंतर
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.
कब किसका उपयोग करें
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.