Hi, Newbie setup so there could be some elementary blunders, but I've spent two days on it without success and some help would be appreciated. Setup as it stands: Win2003 Server R2 running SnomOne 2011-126.96.36.1996 Alpha Monocerotids (Win32) - IP = 192.168.1.127 No firewall is running on this machine. Snom M9 base station version 9.5.14-a - IP = 192.168.1.128 Handsets will register with PBX as long as STUN is disabled so SIP is getting through, but when an internal call is made from one handset to another, the call connects but there is no audio. This is within the same LAN subnet, and there is no NAT routing anywhere between the PBX and the phones. I have previously tried the setup using 3CX instead of Snom One with the same result. Any ideas?