Re: TOE brain dump

Eric W. Biederman wrote:

The optimized for low latency cases seem to have a strong
market in clusters.

Clusters have captive, no, _desperate_ customers ;-) And it
seems that people are just as happy putting MPI as their
transport on top of all those link-layer technologies.

There is one place in low latency communications that I can think
of where TCP/IP is not the proper solution.  For low latency
communication the checksum is at the wrong end of the packet.

That's one of the few things ATM's AAL5 got right. But in the end,
I think it doesn't really matter. At 1 Gbps, an MTU-sized packet
flies by within 13 us. At 10 Gbps, it's only 1.3 us. At that point,
you may well treat it as an atomic unit.

On that score it is worth noting that the next generation of
peripheral busses (Hypertransport, PCI Express, etc) are all switched.

And it's about time for that :-)

- Werner

-- 
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 / Werner Almesberger, Buenos Aires, Argentina     werner@almesberger.net /
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