Re: PerfHist-TC-MIB

[David Fowler <[e-mail]>]

> Jeff Johnson wrote:

> >
> > 2) The xyzInvalidIntervals DESCRIPTION states simply "The number of
> > intervals for which no valid data is available."  When an agent which
> > supports 96 intervals is initially powered up, should the invalid interval
> > counter be 0 or 96?  In other words, are there initially 96 intervals which
> > are all invalid, or are there zero intervals?
>

Miek heard wrote:

> My interpretation is that xyzValidIntervals + xyzInvalidIntervals always
> sums to the number of intervals which the agent supports.  This implies
> that an agent which supports 96 intervals should report a value of 0 for
> xyzValidIntervals and and a value of 96 for xyzInvalidIntervals when first
> powered up.  (If I got this wrong, I'd sure like to know.)
>

When an agent starts up, it has no valid intervals.  It also has no invalid
intervals. The definition for valid intervals is the latest ds1 draft is:

"The number of previous near end intervals for which valid data was collected.
The value will be 96 unless the interface was brought online within the last 24
hours, in which case the value will be the number of complete 15 minute near end
intervals since the interface has been brought online.  In the case where the
agent is a proxy, it is possible that some intervals are unavailable.  In this
case, this interval is the maximum interval number for which valid data is
available."

The definition for invalid intervals from the same draft is "the number of
intervals for which no valid data is availab"

My intention in the creation of this object was to allow for the proxy case
discussed above.  That is, the number of invalid intervals would be the count of
"missing" intervals on a proxy.  Missing intervals occur when the proxy is out
of touch with the actual interface and is unable to collect some intervals.
With that meaning, my intention was that the number of invalid intervals could
never be equal to or greater than the number of valid intervals since the number
of valid intervals holds the maximum interval number for which there is valid
data.

For example, if the agent has been running for 12 hours, the number of valid
intervals would be 48.  If there was a communication disruption for one hour
during that time, then the number of invalid intervals would be 4.

All we really need to do is clarify that the number of invalid intervals must be
less than the number of valid intervals and that it is intended for the proxy
situation.

Regards,
David

--

David Fowler
Newbridge Networks
613-591-3600