On Wed, Sep 13, 2006 at 11:21:26AM +0200, Jose M. Prieto wrote: > El Martes, 12 de Septiembre de 2006 20:30, Attila escribió: > > On Dienstag, 12. September 2006 11:49 Jose M. Prieto wrote: > > > Once the problem arises, it cannot be "reapaired". The problem with > > > window scaling is that routers that can't handle it drop part of the > > > packets; the greater the scale factor beeing used, the more packets are > > > dropped. The only way to recover dropped packets is retranmitting them, > > > which wastes bandwith.
On the other hand, sending lots of very small packets (which is what happens with Window Scaling disabled; remember 64Kb) does not theorically mean speed increase as it's been written previously. > I have tested here with scaling enabled. Wait. Window Scaling has been created back in 1992 and it's been enabled in the kernel for quite a while ! The problem does not *magically* arise. It only breaks in 2.6.17 because the Scale Factor calculation scheme has been rewritten. There were some 2.6.7 testing kernel which used to break as well because the default scale factor had been increased from 0 to 7! Anyway, the *real* source is broken routers/firewalls which rewrite some packets: those containing the Scale Factor at the very begining of a connection. I tried to synthetise the most revealant articles on this topic [1] [2] in an article on the wiki [3]. > > Will i see this under "errors" in ifconfig on my pc's if it happens? > > I get nothing neither in "errors" nor in "dropped". This is a difficult > problem to diagnose. Your connection is actually up and running even though you can't communicate with some/most hosts. They just don't apparently answer (use WireShark). Read the articles. Thanks. [1] http://lwn.net/Articles/92727/ [2] http://kerneltrap.org/node/6723 [3] http://wiki.archlinux.org/index.php/Configuring_network#Troubleshooting -- Benoit Myard <[EMAIL PROTECTED]> [0x3EEC1AEC]
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