On Sat, 6 Feb 1999 mcmanus@appliedtheory.com wrote:
apparently there's some performance value in this (at least to the immediate user) because they keep doing it in droves. It's not obvious to me why the heck this would be. (warning: I am a protocol guy, but I'm not a dialup guy at all.. and even less of a windows guy)
This has been generally beat to death on nanog in the past. If you weren't around back then, dig around in the archive. I remember one of the subjects being "PC Bozoworld strikes again" or something like that. The short recap is that for some unknown reason the Microsoft TCP/IP stack is broken in some bizzare way that setting down the MTU on a good chunk of the machines out there will result in a dramatic speed increase. Why this occurs, I'm not sure anyone really knows. It would be really interesting to see a study of what the MS stack is doing and why it's faster.
MTU - at least this makes a little bit of sense.. If they're doing HTTP/1.0 stuff with parallel connections then a smaller MTU is going to make that parallelization latency much more effective and perceived performance will go up some.. it doesn't impact full document
Just for my information, does the MTU setting affect <received> packets in some way? My understanding was that a machine wouldn't send packets over the MTU size, but could recieve anything up to whatever the TCP/IP stack writer included in the stack. Guess I'll have to go dig out the RFC's. - Forrest W. Christian (forrestc@imach.com) ---------------------------------------------------------------------- iMach, Ltd., P.O. Box 5749, Helena, MT 59604 http://www.imach.com Solutions for your high-tech problems. (406)-442-6648 ----------------------------------------------------------------------