[lkml]   [2001]   [Aug]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
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
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:58    [W:0.055 / U:0.560 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site