Re: [ippm] Comments on draft-ietf-ippm-framework-compagg-00

Hi Henk:

On Mar 21, 2006, at 10:31, Henk Uijterwaal wrote:

> Phil,
>
>> The problem that I have with this section is that it doesn't give me
>> very strong or concrete reasons for why I want to combine metrics.
>
> Suppose I have a path A-B-C.  I'm interested in the delays between  
> them.
> Now, I can measure all 3 (A-B, B-C and A-B-C) separately.  However, if
> there is a way to add up the delays between A-B and B-C, and get the
> overall delay, then i can see myself some work and diskspace.  In  
> general,
> I'd be interested in the minimum set of measurements that still gives
> me information about the entire network.
>
Sure. But the document seems to be trying to say more than that.  
Maybe I am reading too much into it...

>>  Section 5.1: The problem here is that piece-wise measurements do
>> not necessarily combine. IPDV and re-ordering are examples where one
>> subsection of a network can "undo" what a previous one has done.
>> Putting these together in a straightforward way doesn't give you the
>> right answer.
>
> I agree but can't we just say so?

Of course. I think that my point is that you need to say it.

>
> Henk
>
>
Regards,
Phil Chimento

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