> > Microsoft has recently addressed the NAT traversal issue for multimedia > > scenarios by shipping Messenger in Windows XP and it uses universal plug > > and play protocols (www.upnp.org) to open holes on upnp capable internet > > gateways. There are many vendors building upnp capable NATs in 2002. > > Nice. Not really. It's just midcom, which solves some problems and introduces other. It restores one kind of end-to-end function (addressing) while damaging another (routing transparency). Melinda