I recently deployed 3 SX20 in a costumer. The SX20 function without a VCS or other gatekeeper and they works with one to one NAT.
The problems starts when I make a call to a specific customer that have a Polycom View Station 5.1FX. When I make a call the costumer can hear and see me, but I can only hear him...
I could not capture any log, but I taked this print from the SX20:
There is some kind of incompatibility with this model?? The constumer sad that the firewall is OK, and there no rules bethwin the two sites.