Backhaul may have been low, but how did you do congestion control? . . . T
On Mon, Dec 1, 2008 at 2:47 PM, Allen <[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] > http://lists.zooko.com/mailman/listinfo/p2p-hackers >
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