I have a FreePBX server hosted as Vultr and every now and then when a call comes in the systems doesn’t register any phones and the call is lost. I have created a work around that checks if there aren’t any phones registered and if so the call is routed to an external number. I would however rather solve the issue and the first thing I thought was moving to TCP instead of UDP. I opened a port on the firewall, enabled TCP under SIP settings, changed the default port just in case. I then changed the account settings in one phone so that it connects via TCP, but the telephone keep trying but eventually fails.
What can I do to troubleshoot? Is there anything other I should do? And any other ideas concerning the no registered phone issue? When this happens, internet is still up btw.
Set up either sip debug or PJ Debug depending on what protocol you’re using. Then capture the PBX logs again you’re going to have to capture a broader set of logs as the registration errors will likely not be part of an individual call.