hmm... it looks like you are trying to define a protocol rule for a complex protocol. Have you already tried to use the H.323 application filter and Gatekeeper, because the product seems to support that? If that does not work, create an open protocol (all IP traffic) and open site&content rule (all destinations, all content) and make sure the Firewall client is installed.
I have no experience with that product are service, but did you try the H.323 configuration?
Also, in order to get some understanding of how the used protocols are working, install Ethereal on the workstation, place the workstation outside of ISA and capture a session.
Next, make sure the Firewall client is installed on the workstation and you have an open protocol and site&content on the ISA server. Maybe a fresh install of ISA server is recommended too. Verifiy also you have enabled the logging of all fields in ISA server. Now, with the workstation behind ISA, capture again a session. The analysis of both the Ethereal traces and the ISA logs should give you some clue why it is not working.
Hi! Sim, I too had problems setting up Infogate VoIP behind ISA. I tried other way. I installed a machine outside ISA, and installed Tiny Personal Firewall on it. Then went configuring the VoIP. Tiny Personal firewall gives out all the things in real time related to any outbound or inbound access with detailed IP address and ports being used to connect. Using this logs I created appropriate protocol rules and filters and VoIP was working ok.