If you are running as Asterisk or Asterisk-based server and find that your registration-based trunk shows a status of "auth sent", the connection between your server and our termination server(s) has been interrupted and asterisk has timed out re-registering.
This usually means there is an underlying issue (connection problems), however the problem can be worked around by telling Asterisk to keep re-trying registration indefinitely, so whenever the problem may occur, Asterisk will re-register with the connection is re-established.
Add the configuration lines:
to you sip.conf configuration file. (note on some Asterisk derivatives, this may be sip_additional.conf or similar).
This configuration needs to be added as a global setting and not within a trunk configuration.
If the issue is re-occurring, we suggest diagnosing the problem with MTR traces and similar connectivity diagnostics.