On 28 May 2010, at 17:39, David Conrad wrote: > On May 28, 2010, at 8:57 AM, Arnt Gulbrandsen wrote: >> Consider bittorrent. Bittorrent clients generally can run behind NAT, but in that case they have to be on the same ethernet as the NATbox, so it's a safe bet that the bittorrent USER has a real address. Am I stepping out on a limb if I state that most users can run bittorrent? > > No idea. No clue how popular bittorrent is. I was under the impression that the vast majority of folks on residential-level connections were sitting behind a NAT box. Perhaps my impression is wrong? BitTorrent is popular, yes. People at home *are* behind NAT boxes, with all the usual pain that implies *. It's just that BitTorrent, being a straightforward TCP protocol with no embedded payload addresses **, can operate behind NATs, and those NATs can be configured either manually or automatically by users or their client software ***. If the NAT should move to the ISP, it seems possible that this is no longer true. Cheers, Sabahattin * Subjective, I know, but people for whom NAT is not a problem are not full participants of the Internet, and do not use it to full potential. Most of them think the web is the Internet. I regret losing my public addresses to the cloud. ** Actually, BitTorrent does allow clients to tell trackers their addresses, for example to get around proxies; in such cases dynamic addresses are a problem, as are cases where tracker and client live on the same machine, as happens when publishing. This doesn't affect most users though, because trackers default to taking the public IP address of the connecting client as the peer address given to other clients. *** Of course, there's still a learning curve, in which users will sooner or later become acquainted with the mechanics of port forwarding and all that; it rarely "Just works". I'm reluctant to admit everybody capable of comprehending this stuff at first blush; certainly there are many peers who are firewalled and thus get reduced speeds. _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf