I have a customer who recently changed from an Axxess with an IPRC card for two remote phones to an HX system. We have been able to get the phones to connect to the system, but the audio isn't working.The ports we have open in the firewall are:
5566
5567
6004-7039
5004-65468

NAT address type for each phone is set to NAT.

Anything else I should be looking at???