Subject: Re: [Tsvwg] Separate header checksums and WiFi

From: Randall Stewart <[email-masked]>
Date: Sat, 17 Feb 2007 06:04:13 -0500

Michael Welzl wrote:

> 
> I'm sending this note to TCPM, TSVWG and DCCP because there
> are similar mechanisms there (DCCP: the Data Checksum option; SCTP:
> http://www.ietf.org/internet-drafts/draft-stewart-sctp-pktdrprep-06.txt
> although I just noticed that this is apparently not a WG item...
> still, it's SCTP related).
> 
> 

Michael:

One comment on the above... the pktdrp document deals not with
checksums getting to or not getting to transport.. It is
designed to interact with a cisco product that runs over
satellite networks. Where the router learns that some packet
was dropped and what it sends back to the SCTP sender is
the whole intact packet that it could not get through
the satellite link. aka

  SCTP --->- R1 ///// satelink ////  R2 --->- SCTP

It is R1 that has a copy of the packet, and realizes
it had a corruption over the link between R1 <-> R2.
and R1 then sends back the notification.

If R2 sent back the notification then we would see
a similar thing as in your testing...

R

-- 
Randall Stewart
803-345-0369 <or> 815-342-5222(cell)