Subject: RE: [Diffserv] Counters in the classifier

From: "Weiss, Walter" <[email-masked]>
Date: Tue, 19 Dec 2000 14:06:13 -0500

I have to agree with Andrew here. I have three distinct problems with this
proposal.

1. Current implementations may be capable of supporting this new addition to
the MIB, but many will not support as many counters as classifier elements.
Hence, partial compliance would be interpreted by many implementations to
mean available on some classifier elements but not others. This in turn
results in an interpretation problem. How does one determine whether the MIB
variable means anything or not? This will likely be address in proprietary
ways in effect undermining the value of the standard in the first place.
This is why I favored either a level of indirection or an additional MIB
variable indicating the usage of the counter.

2. While I see the value of the notion of debug-able classifiers, I would
point out that the need to debug classifiers have been around long before
DiffServ. Hence, I would expect that debugging capabilities for other
DiffServ components such as meters, droppers and schedulers can't be far
behind. Therefore, something more comprehensive should be considered.

3. Classifiers are one of these key components that are likely to be used in
many other contexts beyond DiffServ. Will other datapath configuration
oriented protocols define their own version of classifiers or will the DS
classifier be applied more broadly? If every WG defines it's own version of
a classifier, interoperability between MIBs will become a serious problem.
If other WGs start using the DS MIB and expanding it with additional
forwarding elements, there are obvious implications on the generality of the
existing forwarding elements already defined in the MIB. I realize I am
expanding the scope of the MIB beyond DiffServ with this comment, but it is
one more reason for me to take a minimalist view for the time being.

regards,

-Walter

> -----Original Message-----
> From: Andrew Smith [mailto:[email-masked]]
> Sent: Tuesday, December 19, 2000 11:42 AM
> To: Fred Baker
> Cc: [email-masked]
> Subject: Re: [Diffserv] Counters in the classifier
> 
> 
> I'd object strongly to this change then - I'd like to see 
> quite a lot more 
> support for this idea before declaring WG consensus on this 
> change. Making 
> "debug counters" a mandatory part of a MIB like this is not a 
> good way to do 
> standards.
> 
> Andrew
> 
> Fred Baker wrote:
> 
> > At 06:32 PM 12/15/00 -0800, Andrew Smith wrote:
> > 
> >> And the intent is for implementation to be optional for RFC 
> >> conformance/compliance purposes, correct? (of course it 
> might become 
> >> mandatory for commercial compliance :-))
> > 
> > 
> > Nope. I don't do optional variables. It just means that 
> many current 
> > implementations (including some of mine) are not quite compliant.
> > 
> > 
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> > 
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ent/maillist.html 

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