Re: [Teas] Rtgdir last call review of draft-ietf-teas-actn-info-model

[Eric Gray <[e-mail]>]

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 last call and IESG review. 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 Last Call comments that you receive, and strive to resolve them through discussion or by updating the draft.

Document: draft-ietf-teas-actn-info-model
Reviewer: Eric Gray
Review Date: April 27, 2018
LC End Date: April 27, 2018
Intended Status: Informational

*Summary:*
Draft Status: Almost ready with minor issues and NITs.

Note: this is not a YANG technical review.

Minor Issues / Questions:
====================
As a general minor question, when instantiating  a topology including only member information, is it assumed that - given a list of members - each member is bi-directionally connected to every other member, are end-to-end member connections pairwise (e.g. - allowing setup of a hub and spoke topology), or is it necessary/possible to define directionality (e.g. - allowing setup of a distribution tree)? 

Note: This should probably be explicitly stated, though section 5.3 seems to imply that both connectivity and directionality are supported (at least the way I read it).

Section 3, top of page 6: while this draft is intended to be informational and does not refer to RFC 2119, the wording "at a minimum" and "should be supported" is inconsistent (or arguably redundant).  I recommend omitting the 1st part ("At a minimum,") making the sentence read instead "The following VN Action ..."
A similar issue applies to the 2nd paragraph in section 4.

Section 3.2, VN Modify: It looks as if this section needs to include text similar to that in section 3.4, given the possible topology types described in section 3.1.  In addition, you may want to restrict what is allowed in a VN Modify to actions consistent with the VN topology type previously instantiated.

Section 3.6, VN Query: In addition to certain NITs, this section should make it clear that the "topology view" returned by VN Query would be consistent with the topology type instantiated for any specific VN.

Section 4, Traffic Engineering (TE) primitives: Does it make sense that the TE actions should be supported at the MPI consistently with the type of topology defined at the CMI, or are they independent?  Section 4.4 seems to imply that consistency is expected.

Section 5.2, VN Service Characteristics: in the shared risk discussion (towards the top of page 12), it is difficult to indicate (with any accuracy) what the shared risks are for a topology type consisting of just a list of members.  Is this limited to topologies of the type that includes (virtual) link and node information?

Section 5.4, 1st sentence: VN Member is not equal to end-to-end tunnel.  I suspect you mean "VN member pair."


NITs:
===
In several sections, the use of capitalization is inconsistent in the section titles that include the word "primitives."  See sections 3, 4, 7 and 8 in the ToC and in the text.

In the paragraph under Figure 1, "there of" should be one word ("thereof").

Same paragraph, "MDSC to MSDC" should be "MDSC to MDSC" (referring to a hierarchy of MDSCs).

Section 2, 1st line: "provides ACTN common ..." should be "provides an ACTN common ..."

Section 3.6, 1st paragraph: there are minor grammar issues with the entire paragraph.  I suggest rewording along lines as follows (minimal change):

"VN Query refers to an inquiry pertaining to a VN that has already been instantiated.  VN Query fulfills a pull model that permits getting a topology view."  

Note: see related minor issue above.

Section 4, 1st line: "... list of main ..." should be "... list of the main ..."

Section 5.2, toward the middle of page 11: "... for the required the service ..." should be "... for the required service ..."  In the very next sentence, "constrains" should be "constraints" and "VN Constrains" should be "VN Constraints."

Section 5.3, bottom of page 13: "Access point identifier ..." should be "Access Point Identifier ..."
In the next sentence, "creation" should probably be "instantiation"

Section 5.3, top of page 14: "... his own ..." should be "... their own ..."

Section 5.6, last sentence in 1st paragraph: should be reworded as:

"... is composed of virtual nodes and virtual links." ("is comprised of" is an incorrect, idiomatic, usage, and "virtual" and "and" need to be shifted around).

Section 5.7.1, 1st sentence: "from higher controller" should "from a higher controller."

Toward bottom of page 18: "Set Priority ... priority to taking ..." should be "Set Priority ... priority for taking ..."

Section 9, 2nd sentence in 1st paragraph: "confidentially" should be "confidentiality"
Same section, 2nd paragraph "... regardless these ..." should be "... regardless of whether these ..."

--
Eric