What bothers me is that using a comprehensive calculation (input and
output combined) on ANY full-duplex connection seams meaningless. What
difference does it make if there is still bandwidth to spare on the Rx
side when the Tx is maxed out?
Your thoughts??
DaveC
Yes: when I say 5 minute movin average, I mean the exponential average.
I have the formula around here some where.
EA Louie wrote:
>
> the definition of load from Cisco:
> Load on the interface as a fraction of 255 (255/255 is completely
> saturated), calculated as an exponential average over five minutes.
>
> I don't personally have access to the formula, nor could I find it on
> Cisco's website.
>
> If this were a multiple choice problem on the certification exams, I'd rule
> out answer 2, because neither input or output is comprehensive in and of
> itself
>
> If 'moving average' means exponential average, then I'd choose answer 1 in
> conjunction with answer 3.
>
> The utilization (based on the sh int load value) doesn't make any sense
> *unless* the bandwidth parameter on the interface is set to reflect the
> actual bandwidth of the circuit.
>
> We had a tool once that extracted both the input/output bps averages and
the
> drops, and calculated *them* across a few seconds against the circuit
> bandwidth - it gave us a little better granularity and accuracy, especially
> if the drops corresponded with higher 'load'.
>
> Also, my experience has been that as the sustained (not burst) pps/bps
> interface utilization approaches the CIR bandwidth of a frame relay
circuit,
> the performance of the PVC starts to degrade. Lots of buffered packets
will
> tend to do the same, so bursts on a point-to-point serial link cause the
> same problem.
>
> ----- Original Message -----
> From: "David Chandler"
> To:
> Sent: Thursday, April 26, 2001 1:05 PM
> Subject: Utilization/load Calculations [7:2167]
>
> > Hi all:
> >
> > How is the "Load" calculated on a serial interface, or any interface for
> > that matter?
> >
> > Does it:
> > 1. Use some weird formula like the 5 minute moving average? > dreamed
that thing up?
> > 2. Use the greater of the input or output bps?
> > 3. Add the current (input + output) bps together and ratio it against
> > the max possible (input + output) bps?
> > 4. none of the above. >
> > We often use ciscoview to monitor circuits for error, dropped packets,
> > input/output bps etc. (It is a lot better than having to keep refreshing
> > your telnet sh int..sh int...sh int..) The utilization which comes from
> > the load never really seems to make any sense. For example: if the Tx is
> > maxed out the utilization does not indicate it... I gave up looking at
> > load/utilization a long time ago. Unfortunately my coworkers seem to
> > think that unless the utilization (via Ciscoview) is high that the slow
> > response issues have to be caused by something else. Needless to say;
> > when the circuit is upgraded and the slow response issues clear, there
> > is a lot of political knife sharpening...
> >
> > TIA
> >
> > DaveC
> >
> > PS: I did check archives. After 100+ messages not telling me what I
> > wanted to know; decided this was a group Question.
> > FAQ, list archives, and subscription info:
> http://www.groupstudy.com/list/cisco.html
> > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=2185&t=2167
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
