We recently got an IP Office 8.1 installed in our network and have been dealing with Avaya trying to get the softphone to work over a standard PPP VPN using TMG 2010. They've had the ticket opened for almost 2 months now with randomly asking for traces every other week. I was wondering if anyone here is using TMG 2010 and have successfully have the softphone up and running using the VPN. Yes, it works internally. And rules are in place to allow SIP UDP port 5060, and TCP port 80, from VPN to internal. HELP!