Subject: Re: draft-ietf-ippm-npmps-01.txt

From: Al Morton <[email-masked]>
Date: Tue, 09 May 2000 08:32:06 -0400

[email-masked],
New Draft, a few more suggestions:

Section 3.2, first Paragraph, 3rd sentence:
"End-to-end delay may be best managed in the general case 
by assigning maximum per-domain quotas (e.g. 50 ms for a 
particular IP domain)." 

I agree that in some cases, delay can be managed
on a per-domain basis by setting only a maximum. An example
would be where the max delay threshold for a domain
is very low (e.g., 10 ms), and the application is fairly
tolerant of end-end delay variation.
However, the general case must evaluate:
* Domains with long 1-way delays (>100 ms).
* Domains with considerable delay variation (100 ms Max, >80 ms range
for a sample).
* Applications of periodic streams with stringent delay variation
requirements.
So the general case should include both delay max and some measure of
delay variation (ipdv, or 1-way delay range). You could mention this
general case, then go on to describe the case where a Max delay quota 
may be sufficient.

Section 3.5.2 Paired one way measurement, second paragraph.
"Moreover, paired one way delay measurement emulates a full-duplex
VoIP call more accurately than a single one-way measurement only."

To motivate paired one way measurement, it may be helpful to cite
the possible reasons for better accuracy.  For example: 
- Performance of some 1-way links depends on conditions in the reverse
direction.
- Many two-way real-time applications have unsatisfactory performance if
packet transfer suffers in a single direction.

(more to follow)
Al