You need to setup new protocol defenition in ISA for Yahoo messenger messaging, webcam and voice.
For the Messaging use TCP port 5050
For WebCAM use TCP port 5100
I tried the above and it worked for me. However, I am still having problem with my voice after I set up the TCP port 5000-5001 and UDP port 5000-5010.
Could someone help me out with this please? Please specify outbound and inbound in your reply.
thanks