Who wants SACK? (Re: was My planned work on networking stack)

Petri Helenius pete at he.iki.fi
Wed Mar 10 13:08:20 PST 2004


Brooks Davis wrote:

>The problem is that the BER of a typical optical link is high enough
>that the link will almost certantly discard at least one packet before
>you get out of slow-start and once that happens it, AIMK means it take
>hours or even days to get back up to the top even assuming you don't
>lose further packets.  This isn't a problem for most people, but it's
>definalty a problem for the HPC community.
>
>  
>
BER is usually combatted with technologies which embed redundant bits 
into the datastream so an occasional bit error does not take out a 
packet. In conjuction of 10GbE this would probably mean G.709. I would 
be happy to learn whether the typical link has BER of 10E-15 or 10E-12 
and how fast retransmit plays in the picture of losing a bit every ten 
minutes or so.

Pete



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