[c-nsp] Flow Control and 10GE interfaces

[David Hughes]

On 24/11/2009, at 3:50 AM, Brian Turnbow wrote:

> The nexus family does PFC (no it's not a card, they reused the acronym)
> http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/white_paper_c11-542809.html
> Basically enables sending a pause per class.
> They did it for FCOE and it is proprietary , the white paper has the standard mumbo jumbo about 
> how it is becoming a standard and everyone is adapting cisco's proposal..



That info is a little dated.  Sure, in "Datacentre Ethernet" days when Cisco where out there alone doing this stuff then yeah, it was proprietary.  Now that's not the case.  It all comes under the CEE banner  (Converged Enhanced Ethernet) and is being formalised by the IEEE as Data Centre Bridging. In particular you'd be interested in the following standards :

802.1Qbb  (priority based flow control)
802.1Qau  (congestion notification)

See http://www.ieee802.org/1/pages/dcbridges.html for all the gory details.

But, in Cisco kit, only Nexus does it.  There other vendors (Brocade / Foundry for example) that can support it and even folk like BNT are making noises.  Could be light at the end of the tunnel.


David
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