Re: PerfHist-TC-MIB

[[e-mail]]

> > I remember somewhere in the draft it is indicated that some values might
> > decrease, i.e., not 'monotonically increasing'. For example, some seconds
> > may be counted as "Errored Seconds" but later it is found that they should
> > not be counted in (this decision can not be made any earlier), so you will
> > have to subtract number of them (seconds) from the total count.
> > 
> 
> Are you serious ?
> 
> This is 'flaky behavior' in any equipment ! After a second has expired,
> it was
> either 'errored' or 'non-errored'.  If the equipment cannot make a
> determination,
> it cannot just increment the counter and change its mind later.
> 
> I sure hope there is no such product out there.  Do you have one like
> that ? ;)

anybody who has sonet equipment compliant with ANSI T1.231 has
equipment like that.  an errored second is an errored second unless
it's an unavailable second.  unfortunately you don't know if it's an
unavailable second until up to 10 seconds in the future.  so if you're
doing real-time couting in sonet equipment, you may have to "correct"
counts up to ten seconds in the past as the interface moves in and out
of unavailable time.

the latest sonet mib draft (draft-ietf-atommib-sonetng-02.txt) covers
this in detail, as well as covers a mechanism that utilizes a
10-second shift register to avoid having to make the corrections.

/jeff