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Re: 95th Percentile again (was RE: C&W Peering Problem?)

  • From: Jim Mercer
  • Date: Sun Jun 03 22:51:35 2001

On Sun, Jun 03, 2001 at 01:34:08PM -0400, Alex Rubenstein wrote:
> > i'm not super-duper, but i'm tier2 and the bulk of my business is wholesale
> > (the basic service is a connection and transit, nothing else).
> >
> > most of my customers are ethernet connected, and some customers share
> > an interface.  i got into this before it was cheap to do 802.11q
> > switching, so my billing system needed to deal with multiple customers
> > on a single ethernet.
> 
> Thats irrelevant; look at the counters on the customers switch-port.
> Doesn't matter what VLAN (or none) they are on.

ah, well, again, i was using multiport bsd implementations, not switches.

as it stands, i'm fairly content using the cache flow from the cisco's.

one day, i might actually install a full 802.11q compliant switching
framework, but, well, not today.

my comments were intended for those who may not have the economic or
political management support for a full 802.11q switched framework, and that
it is possible to do reasonable billing without going there.

your mileage may vary.

> > its working for me.
> 
> Is it? Have you verified that, in actuality, it is accurate?

accurate?  unless you have certified CPA's inspecting each packet of traffic,
on what basis are you determining accuracy?

you have to trust something.

> Having done a small-bit of verification on flowstats versus counting bytes
> via SNMP, i have caught some interesting anamolies.

i have seen a number of interesting anomalies on both the flowstats and SNMP.

flowstats (if you have sufficient storage) at least allows you to replay the
events leading up to the anomaly.

SNMP, as good as it is, is basically use it or lose it.  either you trust
the data, or you don't, as there is not a lot of detail there.

aside from the fact that i'm yet to find a way to use SNMP/cisco to allow
me to do accurate (without totally swamping the CPU) details of per-subnet
bandwidth usage without per subnet interfaces.

-- 
[ Jim Mercer        [email protected]         +1 416 410-5633 ]
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