Determining the ip-address of chatting person

This question used to raise from the time i was studying my networking course. Suppose I am chatting with some other person on the g-talk and if I capture the packets then whose ip address it would be whether it would be the ip address of the person whom i am chatting with or of the relay server in between.

Is there any way i can get the ip ad开发者_Go百科dress of the person whom i am chatting with ??

Generally - no. Since there is no way to establish direct connection between ANY two hosts (two peers both behind NAT will not be able to connect directly), all communications should occur through relay server, so any packets you capture will be from and to relay server.

But GTalk developers MAY implement a feature to connect two chatting peers directly (if possible). In that case you will be able get the other person's IP address.

Also relay server may simply report other person's IP address.