[c-nsp] Flow Control and 10GE interfaces

[Kevin Graham]

> so you have one ingress port ("the NAS"), 20 egress ports ("the clients").

> 
> Egress port 1 fills up.
> 
> What are you going to do?  Flow-control (-> slow down 19 other ports)
> or drop?

Agreed, egress queuing and "flowcontrol send" seems logically flawed, but 
the NAS case I see cited is "flowcontrol receive" on the switch side.
In this case, egress port pauses, backs up, and further traffic to it
drops -- there's no reason I can see for this have any impact to other
ports.

In an edge-device (NAS, server, whatever) it seems far more likely that
the -host- is what needs the pause (flowcontrol receive), not the switch
(flowcontrol send).