[nm-wg] Hierarchy Draft comments

[Eric Boyd <eboyd@internet2.edu>]

Greetings,

Here are my comments on the document. (I"ll submit these to Gridforge as well.)

Overall, I think the document is a valuable and useful contribution to GGF.

Specific Quibbles
=============
1) In Section 4.5, the last sentence says "We believe that in general the 
guiding principal should be return as much of the pertinent information as 
possible and let the querying application make the decision [as to] what 
information to use."

I disagree with this statement and think it contradicts the NMWG request 
requirements document 
(https://forge.gridforum.org/docman2/ViewCategory.php?group_id=63&category_id=513) 
which says:

 "It should be possible to specify a query (albeit a simple one) with a 
minimum amount of
information. This would be a test start and end point, a time, and a test 
type (metric/measurement).
Note: this is a definition of the minimum set of information required to 
request a test or historic
data, not the minimum set of values to be contained in a message based on 
the schema. Default
values could be defined for non-specified information.
Although obviously not a direct requirement of a request schema, it is 
nevertheless expected that a
minimally specified request should result in a correspondingly minimal 
response, e.g. containing
time information and a measurement value only."

At the very least, I think we should drop the sentence altogether.

At the very most, I'd like to replace it with the statement from the 
request schema requirements document or something like it.

My intuition, based on the reactions when this topic was discussed in 
Berlin, is that there is not unamity among the group on this point and that 
we should hash this point out in the very near future (as it strongly 
impacts the request schema and the interaction of the request schema and 
response schema).

2) In section 5.1, 6.1, and 9.2, not to beat a dead horse from Chicago, but 
I still think the "hoplist" is misleading for a round-trip measurement 
associated with a path in the instance where the path is assymetric. I 
think there should be a way of indicating 2 hoplists, or, if only one is 
given, assuming the path is symmetric.

3) In section 5.3, where would optical splitters along a lightpath fall? 
They are essentially "observation points" but not internal nodes.

4) In section 7.1.1, in the first paragraph second sentence, I would change 
it to "However, in general it is not [yet] posssible [to] get access to 
this information for network switches and routers in different 
administrative domains. For example, an end-user is [as yet] unlikely to be 
able to access SNMP information from a commercial ISP's network."

In a sense, this is what many projects (e.g. piPEs) is trying to enable in 
the academic world and thus eventually in the commercial world. We 
shouldn't give up before we start.

--Eric

PS Note that at least one of the links on the NMWG webpage 
(http://www-didc.lbl.gov/NMWG/) does not point to the GridForge site. In 
specific, the link the current request schema requirements should point to: 
https://forge.gridforum.org/docman2/ViewCategory.php?group_id=63&category_id=513, 
not http://rtlin1.dl.ac.uk/nmwg/.

Eric L. Boyd
eboyd@internet2.edu
734-352-7032 (work)
734-834-6708 (cell)

Office 230
Internet2
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