travis kalanick wrote: > Backhaul may have been low, but how did you do congestion control? . . .
Wasn't an issue then and I'm not sure it would be now in the version I worked on as there were no intermediary servers for the file transfer. It may be different now. One established an initial connection between two end points via a server, this was done via simple TCP and a couple of packets containing information about what was coming. This also created the IP to IP connection. Then one that acted as server and the other as client. Wouldn't scale, probably, to the needs of a large community. However, I'm not sure. Allen > T > > On Mon, Dec 1, 2008 at 2:47 PM, Allen <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> wrote: > > > > travis kalanick wrote: > > If uTorrent's UDP implementation results in a more aggressive > TCP, there > > is certainly the possibility that uTorrent could create massive > FAIL on > > the Internets. > > > > Anyone who's created/tuned a distributed-UDP-based-TCP-like protocol > > (e.g. David Barrett, Matthew Kaufman, Alex Pankrotov) knows the > delicate > > nature of how distributed-TCP-in-UDP works, and how it can go very > > haywire with just a couple of well-intentioned tweaks. > > Hi, > > Back about 1998 a company I was working for used a UDP wrapper > around TCP packets. Each UDP packet had a unique number in the > header for a given message/file transfer and the TCP inside did > as well. The client collected them, found which ones had been > lost in transit and sent a "resend message" for just those > packets. Worked very well in very high RTT latency connections, > like satellite and cell phone. The latency we measured on, if I > recall correctly, Dokomo got as high as 51 SECONDS! although it > averaged about 3 to 4 seconds and satellites was about 2 seconds > RTT. TCP would never work, but UDP did. All that was needed was > for the client to order the packets correctly and ask for any > missing ones. The back haul went from about 13% for TCP on low > latency links to under 1% using UDP. Even on high latency links > we never saw much over 1% back haul traffic. > > One of the fun things about it was that the whole message/file > could only be collected at end points due to the various routes > UDP took at that time. > > The company still exists. It's now called Venturi Wireless at > http://www.venturiwireless.com/ > > Best, > > Allen > > There are only 11 types of people in the world; those who > understand binary; those who don't; and those who could care > less, they just want the g^&d$%^ computer to work! > > > _______________________________________________ > p2p-hackers mailing list > [email protected] <mailto:[email protected]> > http://lists.zooko.com/mailman/listinfo/p2p-hackers > > > > ------------------------------------------------------------------------ > > _______________________________________________ > p2p-hackers mailing list > [email protected] > http://lists.zooko.com/mailman/listinfo/p2p-hackers _______________________________________________ p2p-hackers mailing list [email protected] http://lists.zooko.com/mailman/listinfo/p2p-hackers
