What it means
A proxy acting as a gateway got an invalid response from the server downstream of it. The fault is one hop further along, not with the proxy itself.
SIP/2.0 502 Bad Gateway
Common causes
- A downstream trunk or gateway returned a malformed or invalid response
- The next hop is unreachable or returning garbage
- A DNS problem resolving the downstream server
How to fix it
- Check the health and reachability of the downstream route
- Verify DNS for the next hop resolves correctly
- Contact the upstream provider if the bad response comes from their side
See it in your own trace
Paste a full SIP or Asterisk log into the decoder and ladder tools to see exactly where this response appears in the call and what led to it. Everything runs in your browser, so your logs never leave your device.
Open the SIP decoder
See how a SIP call flows