XMPP file transfer

[Prateek Sharma]

Hi folks,
         I use pidgin to connect to the gtalk servers. I am behind a
proxy. I noticed that i am not able to use the file transfer feature
with gtalk.
         When the other-end is also using pidgin, however, i get the
maximum speed supported by the network (the other party is on the same
LAN). I was really amazed by this. So my question is: how is pidgin
able to transfer files at the LAN speed? How does it figure out that
the transfer can be made without using the jabber server?

PS: Im sorry for posting such a n00b qs on the mailing list. I wouldve
asked it on IRC, but thats not allowed by the proxy. :(