Sniffing the Google Talk Packet Stream
Interesting stuff. James Seng has sniffed the Google Talk packet stream. It’s vanilla XMPP (the Jabber Protocol). One neat innovation is that each Google Talk client is a STUN server, thus replicating Skype’s ability to traverse firewalls, in a standard way. How long before we see this in SIP clients?

August 27th, 2005 at 4:04 pm
While this might seem smart, I’m not sure it works. In a typical situation where both GT clients are behind a firewall, they still would not be able to talk since the initial STUN binding requests would not make it through the firewalls.
More likely they are including a STUN server to be compliant with ICE, another standard (fortunately) used to do NAT traversal.