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* Posts by Erik Smith

1 post • joined 11 Oct 2011

Mixing network traffic types on Ethernet

Erik Smith

A couple of minor points

I have a couple of minor points:

1. The statement, "...FC MTU is 1440 bytes..." should be 2240.

2. The statement "When an Ethernet frame is received on a Switch, it is placed into a memory location and waits for forwarding. For storage traffic this isn’t acceptable since the end-to-end delay should be as low as possible to ensure that storage throughput is fast. The Ethernet Switch is configured to immediately service the buffer that contains storage data as well as to forward the frame at the next interval." >> I’m not sure what is meant by this, FCoE Frames are routinely stored in a buffer and will be forwarded when bandwidth is available. As Greg mentions later, ETS (802.1Qaz) ensures that each priority is allocated a certain amount of bandwidth and in cases where the bandwidth is being fully utilized, or there is upstream congestion, FCoE frames will be stored in a buffer (sometimes for extended periods of time)..

Regards, Erik

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