Subject: [ippm] framework-compagg-05 comments

From: "Loki Jorgenson" <[email-masked]>
Date: Fri, 30 Nov 2007 17:29:55 -0800

Some comments below to Reza's comments (in BLOCKS):

Also, some other general comments:

Section 3.2 - there is a reference to "true path" with no entry under
Terminology to define it.  Is it related to "ground truth" (which is
defined)?  If it is not intended to be a unique term but only a
descriptor, I would suggest changing it to something more like "actual"
(as used in "ground truth").

Section 4.1 - with regard to weighting function and transient vs.
intransient measures (see comments further down).

Section 4.5 - second sentence has "would be a the delay"

Section 5.

As I was dealing with IP issues today and aspects of viral licensing, is
it appropriate to include in any composition metric description IP
references to embedded proprietary metrics and/or use of standards?

Otherwise, I note, most of the requirements in section 5. are technical.

On a more general note:

I would suggest that there are "ground truths" that fall into two
categories - I will term them "transient" and "intransient" - that
reflect their variability (primarily with respect to traffic).  For
example, (minimum) delay is intransient w.r.t. traffic - it may vary due
to route change.

Most measures and metrics tend to involve transient effects and so
averaging is more typical for those (instead of minima).  There are
underlying temporal constraints that possibly should be noted with
regard to transience.  That is, aggregate temporal measures over
times-scales exceeding known variation lengths may be misleading (i.e.
aggregating over a day when transient traffic effects are known to vary
on 24 cycle).  At least describing these might be appropriate.

Perhaps this kind of thing is implicitly part of any weighting function
(as described in 4.2 regarding spatial aggregation)?

It seems in any case that there are measures that assess the network
with respect to its design (how big, how long), and with regard to the
traffic and related performance (how much, how well).  Intransient
features, independent of traffic, are then aspects of the network
itself, while transient features are about the traffic using it.

If this were considered applicable, I am not yet sure how this would
appear in the document.  Except possibly as a Section 5. requirement
with regard to temporal aggregates than span time periods that are
potentially problematic.    However, this might be subsumed into one of
the other attributes listed there concerning relationship,
justification, or inaccuracy.

Comments?

Loki Jorgenson
Apparent Networks
t   604 433 2333 ext 105
m   604 250-4642

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Message: 1
Date: Wed, 28 Nov 2007 19:27:47 -0800
From: "Fardid, Reza" <[email-masked]>

Section 3.6

R-factor is a valid example of an index as defined here, however, it is
composed of both IP performance metrics and analog metrics.

On this basis, is it within scope of this draft?

Loki> SUPPOSEDLY NOT 2. Scope INDICATES THAT LOSS, LATENCY, AND DELAY
VARIATION ARE THE LIMITS.  BUT THIS IS NOT ENTIRELY CLEAR, I CONCUR, AND
SHOULD BE FURTHER DELIMITED.

Another relevant index composed of IP performance metrics is MDI, per
rfc4445.

Loki> NOTE THAT THIS ON THE OTHER HAND IS NOT AN IETF STANDARD - RFC4445
IS INFORMATIONAL AND MDI A PROPRIETARY METRIC (US PATENT APPLICATION
10/604,997).  OF COURSE, COMPAGG DOES NOT EXCLUDE SUCH METRICS (AS FAR
AS I SEE).

IS THERE ANY EXPLICIT REQUIREMENT WITHIN COMPAGG TO IDENTIFY CONFORMANCE
TO ACKNOWLEDGED STANDARDS (WHATEVER THOSE ARE)?  I DON'T SEE ANY SO I
WOULD ASSUME NOT.

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