SIP 183 Session Progress vs 410 Gone
SIP 183 (Session Progress) is a 1xx Provisional response, while 410 (Gone) is a 4xx Client 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, 410 means that the requested resource is no longer available at the server and no forwarding address is known. This is expected to be a permanent condition.
Description
Used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP.
When You See It
During call setup, especially in PSTN interworking scenarios. The response may contain SDP for early media like custom ringback tones or IVR prompts.
How to Fix
No fix needed — this is informational. If early media is not playing, check codec negotiation and SDP handling in your UA.
Description
The requested resource is no longer available at the server and no forwarding address is known. This is expected to be a permanent condition.
When You See It
When a user account has been permanently deactivated or removed from the server with no forwarding information.
How to Fix
The user is permanently gone. Remove this URI from your contacts. Unlike 404, the server knows the user once existed here.
Key Differences
183 is a 1xx Provisional response, while 410 is a 4xx Client 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 410: The requested resource is no longer available at the server and no forwarding address is known. This is expected to be a permanent condition.
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 410 when when a user account has been permanently deactivated or removed from the server with no forwarding information.
When to Use Which
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 410 (Gone): The user is permanently gone. Remove this URI from your contacts. Unlike 404, the server knows the user once existed here.