On Sun, 22 May 2005 09:51:48 +0300
raz ben jehuda <razb@xxxxxxxxxxx> wrote:
> I do not know if this was ever suggested.so i'll try any way.
> Why not give the user the chance to supply the kernel/card with the
> checksums instead of having the kernel/network card do the work ?
A bad idea for two reasons:
* application data units (APDU) do not match transport data units
for a stream oriented protocol.
* computing checksum is done for almost nothing as part
of the copy from user to kernel space. Modern CPU cache's
make computation cost << memory access cost.
> This is because a user is aware to the data he sends and he can optimize
> the data checksum calculations more than anyone else. for instance a web
> server sends its html pages, which are static data. it can pre-calculate
> the checksums.
Tcp will compute different transfer size's based on the congestion
window of the connection, and header part will be different.
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