這個是剛剛查的
Windows Messenger - voice (computer to phone) 2001-2120, 6801, 6901 from Q324214. NOTE: 6801 is Net2Phone.

MSN Messenger - file transfers 6891-6900 from Q278887. Allows up to 10 simultaneous transfers.

MSN Messenger - voice communications (computer to computer) 6901 6901 from Q278887