[c-nsp] L2 rate limiting (ethernet)

[Christopher E. Brown]

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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