[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: FW: 64 bit counters in MPLS MIBs



Title: RE: FW: 64 bit counters in MPLS MIBs

> From: Andy Bierman [mailto:abierman@cisco.com]


> Remember the '1 hour rule'?  Remember the many discussions
> that led to the text in RFC 1573, sec. 3.2.6?  Remember that
> we don't have Unsigned64 or Integer64 because some people
> objected on the grounds a reasonable '1 hour rule' could
> not be written for these types?
>
> Well, we still have the '1 hour rule' in effect, and therefore
> it would be inappropriate to tell the MPLS MIB people they
> should remove their 32 bit counters.  The correct design
> depends on the possible instances of the counter. For many
> counters, this is to have both 32-bit and 64-bit counters
> and use conformance statements to specify which versions need
> to be implemented.  The 64-bit versions are named with an HC
> in the descriptor (by convention).
>
> This does not mean I supported the '1 hour rule', then or now.
> The rule for Unsigned64 is so bloody obvious it's not
> surprising we missed it: "I need to model a quantity that is
> greater than 2^^32." End of rule.

It should really be called the "1 hour guideline" since the real purpose is to provide guidance as to when to use 32 vs. 64 bits.

I agree that if the guideline applies, i.e.: a quantity greater than 2^^32 will be achieved "quickly", then use 64 bits and do not model the 32 bit counter. As Jeurgen pointed out -- what is the problem that is trying to be solved -- i.e.: is 2^^32 reached "quickly". I don't know the problem that is trying to be solved but I know the guideline and it should continue to be applied.

/gww