When you set up VoIP trunks from the Asterisk server to various providers, what you’re really doing is registering Asterisk as a VoIP client. To monitor the status of each trunk’s registration, use the sip show registry and iax2 show registry commands. Here’s a SIP trunk registration in progress:
kartookpbx*CLI> sip show registry Host Username Refresh State testasterisk.kartook.com:5060 s00567734dr 120 Auth. Sent
Here’s an IAX trunk registration:
kartookpbx*CLI> iax2 show registry Host Username Perceived Refresh State 10.10.10.10:4569 testkartokkring <Registered> 60 Registered
You can also follow VoIP trunk registrations in Asterisk’s detail log output.