Ah, the joys of NAT. Is FS' NAT functionality supposed to be able to detect and handle far-end NAT traversal? I have the following scenario: Endpoints on a LAN connected via the Internet to FS though NAT FS --> Internet --> NAT firewall --> Endpoints Proxying the media works fine but when attempting to bypass media between endpoints all on the same LAN, I would expect FS to negotiate media between them using their internal IP addresses. So if IP phone A at 10.0.0.101 wants to talk to IP phone B at 10.0.0.102, FS should set up the media streams to go directly between them using those internal addresses. However, that is not the behavior I'm seeing. Instead, FS is trying to set up the media between them using their external IP addresses which results in no audio. Is there a way to get FS to handle this properly? I'm pretty sure that OpenSIPS' can detect and handle this scenario and I'm hoping that FS can as well, without having to put OpenSIPS in front of it. Is this just a configuration issue? Many thanks, Phil Quesinberry Q Systems Engineering, Inc. Electronic Controls and Embedded Systems Development (410) 969-8002 http://www.qsystemsengineering.com