Why it happens
- A malformed message or an interoperability bug between vendors.
What to check
- Capture the signalling and look for the message the far end did not like; compare with the vendor’s interoperability notes.
Q.850 cause 111: Protocol error, unspecified
Protocol error, unspecified: a signalling error that fits no other cause.
111
- Q.850 name
- Protocol error, unspecified
- Group
- Protocol errors
- FreeSWITCH
- PROTOCOL_ERROR
- Asterisk
- HANGUPCAUSE=111
- SIP response from a gateway
- 500 Server Internal Error
- In SIP
- Reason: Q.850;cause=111