Re: Polycom PVX v8.0.4 drops the videoconference call at exactly 15 minutes
I had a similar issue with a partner´s firewall. Because the port TCP 1720, used for the H.225 call signaling, maintenance and control, was closed, the call was disconnected. Reason for that was a default tcp timeout programmed on the firewall, which was set to 15 minutes.
In this case, the firewall has been a sonicwall. The solution can be found here