Subject: Re: [lmap] Scope, Use Cases and Users and Which are Mandatory vs. Nice to Have

From: Al Morton <[email-masked]>
Date: Wed, 14 Nov 2012 18:01:20 -0500

At 11:43 AM 11/14/2012, Weil, Jason wrote:
>...SECTION 6 - Requirements:
>
>What is alluded to but currently missing in the current version of the
>draft is a requirement for the active measurement testing to not
>negatively impact the Network under test. This is a key feature in the
>Measurement controller functional requirements that needs to be included
>from day one.
>
>Proposed C-6: The measurement controller MUST ensure that the test
>schedule it provides to measurement clients in its domain is generated in
>a manner that minimizes aggregate test load on the measured network.

+1, I'd even go further and include the metrics measured.

It is an important tenet of the IPPM framework RFC 2330, sec6.2:
    ...
    Finally, some measurement methodologies may be 'conservative' in the
    sense that the act of measurement does not modify, or only slightly
    modifies, the value of the performance metric the methodology
    attempts to measure.  {Comment: for example, in a wide-area high-speed
    network under modest load, a test using several small 'ping' packets
    to measure delay would likely not interfere (much) with the delay
    properties of that network as observed by others.  The corresponding
    statement about tests using a large flow to measure flow capacity
    would likely fail.}

There are many reasons to prefer a "conservative" methodology,
especially if a reasonable projection or model based on fundamental
metrics is possible/available.

regards,
Al