[nsp] ATM per VC stats via SNMP

[warner at cats.ucsc.edu]

On Wed, Feb 26, 2003 at 04:42:02PM -0500, Charles Sprickman wrote:
> Can I ask something of you folks that's a bit OT?  I'm looking to build a
> quick tool that would look something like this:
> 
> spork$ ./showrate.pl 0 149
> *checking 30 second usage on pvc 0/149
> (30 seconds pass)
> *30 second usage on pvc 0/149: 180KB/s in, 50KB/s out
> spork$
> 

===========
In dCEF capable systems, counters on the interfaces keep
tabs of bytes through the interfaces.  These are not the
counters that are read via SNMP.  A clock driven process
transfers the counts to the route processor which adds
them into the accessible SNMP object.  Beating of this
clock with your sampling will cause apparant jitter
in the data rates that really isn't there.

On GSRs I've seen the transfer happen c.a. 8 or 9 seconds.
That would interfere with 30 second measurements.