Last Call Review of draft-ietf-teas-actn-requirements-08
review-ietf-teas-actn-requirements-08-rtgdir-lc-dimitri-2018-02-28-00

Hello,

I have been selected as the Routing Directorate reviewer for this draft. The
Routing Directorate seeks to review all routing or routing-related drafts as
they pass through IETF last call and IESG review, and sometimes on special
request. The purpose of the review is to provide assistance to the Routing ADs.
For more information about the Routing Directorate, please see
​http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir

Although these comments are primarily for the use of the Routing ADs, it would
be helpful if you could consider them along with any other IETF Last Call
comments that you receive, and strive to resolve them through discussion or by
updating the draft.

Document: draft-ietf-teas-actn-requirements-08.txt
Reviewer: Dimitri Papadimitriou
Review Date: 28-02-2018
IETF LC End Date: date-if-known
Intended Status: Informational

Summary:

I have some concerns about this document that I think should be resolved before
it is submitted to the IESG.

Readability should be improved: the document is not easy to read for people not
mastering terms not used in their canonical/CS sense.

It may be appropriate to reconsider the title of this document since most
requirements are qualitative/functional (very limited considerations about
quantitative aspects) or alternatively clarify this point in the abstract.

Comments:

Section 1: several terms are used without providing reference to their
definition. Examples include "orchestration" (is it used as synonym of
coordination -- defined in ACTN-FRAME), "collation", "hierarchical abstraction"
(do authors refer to the well-defined notion of recursive abstraction ? and
what is the minimum of #recursion levels to be supported/expected).

Section 1: the statement " Provision via a data model of a computation
scheme..." is to be clarified: does this requirement imply that the
"computational methods" must be using the same data model as the one used for
network control/operation ?

Section 1: the document refers to various policies (= mapping from state to
actions; hence, at several places the use of the term "policy" seems
inadequate/refers to something else); more importantly, this raises the
following question: what about detection and resolution of policy conflicts
e.g. any requirement in terms of automation in the handling of run-time
conflicts ?

Section 2.1: Clarify the relation between Req.1 and .3, it looks as if Req.1 is
a very generic statement whose specifics are documented in Req.3

Section 2.1: Concerning objective functions document if the requirement implies
that "any" of them would have to be supported or if a min.set of obj.functions
have to be supported on a path and/or graph basis (if this min.set is unknown
at this point in time mention it explicitly).

Section 2.1: Req.8 Would be appropriate to explicit the term " Trust domain
verification" between which entities (ext/int to what ?), what this
verification implies ?

Section 2.2: Req.1 VNS delete/modify/etc. but no "provisioning" action listed,
any reason ?

Section 2.2: Req.3 concerning the " Alternative path computation" does it mean
that an BGP alternate path would be satisfactory as long as connectivity is
ensured ?

Section 2.2: Req.4 in the headline of the section the term restoration is
distinguished from protection, in this requirement not; does it mean that for
path protection there is no involvement besides end-points ? In Req.5 the "
fast recovery/reroute" technique is being used instead. Suggestion is made here
to stick to one terminology throughout the whole document.

Section 2.2: Req.5 specify for the so-called "Large-scale VNS operation"
whether the answer to the operation is expected at the same level of
granularity. Example: query all leaves of a tree is a single command but the
requester could be in turn overloaded if 100k leaves reply individually.

Thanks,
-dimitri.