Polycom PVX v8.0.4 drops the videoconference call at exactly 15 minutes

[KLH]

Hello, I have an activated, registered Polycom PVX v8.0.4 installed on a Windows XP machine.  It can connect its audio/video seemingly correctly using internal IP and external IP via a NAT.

At exactly 15 minutes, however, it drops the call.  What possible causes are there for this type of behavior?

I'm happy to provide any sort of information to help troubleshoot.  Apologies in advance but I am a bit of a novice with this product.

Thanks!

[Uwe_Ansmann]

Hi there...

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