Asterisk Server Dropping Calls at 1 HR. Mark

You can either define a trunk to match calls coming in from your provider, or if you want to keep doing it as anonymous inbound calls (unmatched) then you can add that session-timers=refuse line to the general section of your SIP config as a default. The way to do that from the GUI is to go to Asterisk SIP Settings, chan_sip settings, scroll to the bottom where you see “Other SIP Settings” and in the fields, put session-timers in the left hand field and refuse in the right hand field.

Thanks for all your help. I will see how it goes.

You saw this, right? This, IIRC, is a router/firewall configuration issue on the phone at the remote router. It even has a reference to what to do to solve the problem.