lkml.org 
[lkml]   [2001]   [Aug]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: hardware checksumming
Christian Widmer wrote:

> yes that might be easy for the NIC's transmitting enging when all fragments
> belonging together come one after the other in the transmit-ring.
> but receiving is difficult since different connections can arrive
> simultanously and reslut in interleaved framgents.
>
> something else: you need quite a lot of ram on the NIC to buffer fragments.
> if not it will have to transfer the data twice through the PCI (checksumm are
> at the beginig of a packet not the end). nobody did spend a second on
> thinking to implement all in hardware when the interet protokol was desinged.

You don't have to store entire fragments in a NIC to do
hw checksums. All you need to store is the partial checksums,
and add to them whenever yet another fragment comes in for
that packet.

Helge Hafting
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:58    [W:0.047 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site