chi zhang - 2008-05-04

Hello,
Could any of you help me on how to realize function of file transfer  according to "application/x-msnmsgrp2p" protocol?
I have add file transfer to jml according to  "text/x-msmsgsinvite" protocol .But, transfering file is difficult through firewall because socket port 6891 must be openned.
So please can you give some idea or code  of  "application/x-msnmsgrp2p" protocol about file transfer.

Thanks in advance.