I am a new member to this form but definitely an old lurker. I have been pulling my hair out trying to get a Cisco 7960 with SIP firmware working as a remote client on FreePBX.
I got all the configuration files loaded easily enough via tftp.
The phone would register from a remote location and incoming/outgoing calls worked.
Then 30 seconds later only outbound calls would work. The 7960 would show as unavailable. Nothing in the logs to indicate a fault.
I poured over posts from multiple forums and none answered the problem. So I read every config file and xml file until I figured out what was wrong.
In the XMLDefault.cnf.xml file I modified the following:
6 10 20 20 5 20 20 5 500 3000 70 true None
I wanted to share this with the community since there were no answers anywhere else. And the posts I did find just dropped off without any resolution.