[c-nsp] L2 rate limiting (ethernet)

[Christopher E. Brown]

I have been reading through the ME3400 line docs, but while the docs
seem to indicate that per port ingress policing and egress shaping are
supported I cannot find anything as to limits.


Anyone here running a 200 - 500 mbit ingress/egress police/shape
configuration?


Christopher E. Brown wrote:
> Hoping to pick a few brains on the subject of ethernet rate limiting.
> Context is metro ethernet at the customer prem.
> 
> My take is 10/100/1000 take it or leave it, but of course there is
> demand for various levels from 2Mbit to 500Mbit.
> 
> This is of course an issue.
> 
> The 3550 will only properly do egress (ingress cannot classify IP and
> non IP without using an aggregate policer, only 8 and quickly overloads
> the CPU).  The burst bucket size limit makes "friendly" bursty traffic
> handling limits a non option past the 10-20 Mbit range.  And, in my
> testing, a 200mbit limit on a gig port just doesn't work.  Throw 250mbit
> at a 200 limit and get 162mbit out (from a packet generator, not TCP
> interaction, just the switch throwing away too many packets), or if
> traffic is very bursty (180mbit average with continual bursting to
> 600mbit+) the 3550 randomly crashes.
> 
> The 3750 is ingress only, and has an even smaller burst bucket limit.
> 
> 
> Looking for reasonable CPE switch, 10/100/1000, ingress and egress rate
> limiting on a per port basis (access port or 802.1q trunk port) from
> 2mbit - 500mbit.  No bucket (hard discard) is ok, single bucket better,
> 2 bucket (burst bucket + progressive drop) best.
> 
> 
> Suggestions?

-- 
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Christopher E. Brown   <chris.brown at acsalaska.net>   desk (907) 550-8393
                                                     cell (907) 632-8492
IP Engineer - ACS
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