What are the possible reasons for a SIP register failure

asteriskfreepbxtrunk

I have setup an Elastix box (asterisk/freepbx based) and added a trunk for an external VoIP provider.
When I get to the Asterisk command line interface and type sip show registry I always get the same output, State = Request Sent.

So, since I can't register with the server I can't make calls.
What are the reasons for the SIP registry state to remain in a status sent forever ?

Best Answer

Yes, a networking / firewall issue... lots of possibilities:

  1. Network routing not working from the box: check networking in general
  2. SIP provider unreachable
  3. Firewall(s) in the way of the outgoing request or the answer
  4. A NAT router with SIP options in the way which happens to block internal SIP on port 5060

Time for some network debugging, like pinging the sip server from the freebsd commandline