[c-nsp] Cisco 3550 counters and QoS

[Jon Lewis]

On Tue, 24 Aug 2004, Yuval Ben-Ari wrote:

> I remember this problem when we just started using 3550 for policing
> back then when checking with the product manager/engineer I remember the
> conclusion was that the switch is first counts and only then polices so
> the counters actually show the pre-policing traffic (hope I'm getting it
> right and not misleading)
> so it is a design flaw that cannot be overcome, at least that was the
> conclusion back then.

I wouldn't even call it a design flaw.  These just aren't the counters
you're looking for when it comes to billing.  Assuming it doesn't exist,
cisco should seriously consider adding snmp counters to all their devices
that rate-limit/shape/police so that you can check both octets/packets
to/from an interface and octets/packets forwarded to/from it.  If a 10mbit
policed system is spraying your switch with 100mbit/s of SQL slammer,
wouldn't you expect to be able to see that via the snmp counters?  If a
customer is paying for 10mbit service and rate-limited to it, wouldn't you
want to know who's traffic it was if they were being sprayed with
100mbit/s of data (though only 10mbit was getting through to them)?

----------------------------------------------------------------------
 Jon Lewis                   |  I route
 Senior Network Engineer     |  therefore you are
 Atlantic Net                |
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