Hi
Microsoft has a document describing this. It is Technet document Q218262 which contains the following information:
NetMeeting is not supported in the WTS environment.
MORE INFORMATION
NetMeeting directory servers keep track of who is logged on by email address and IP address. When two users are logged on to a WTS session, they each have unique e-mail addresses, but are sharing the same IP address, that of the Terminal server computer.
Hope this helps
/Hof