Subject: [CDNi] Review of draft-ietf-cdni-metadata-04

From: "Vijay K. Gurbani" <[email-masked]>
Date: Thu, 02 Jan 2014 12:05:57 -0600

Greetings with good wishes for a new year.

During the Vancouver IETF, I volunteered to review
draft-ietf-cdni-metadata.  The review is below, in linear order and nits
and substantive comments are intermixed.

Generally, the document is well written.  I do feel that a set of more
comprehensive examples can add to the understanding of the idea.
Detailed review is below in document-order form.

- S1: s/Specifically this/Specifically, this/

- S3, first paragraph: In the sentence "Metadata properties describe
  how to acquire, authorize, and deliver content from a downstream CDN.",
  I would break down the prepositions depending on who is doing what.
  In the absence of individual prepositions, you are left with applying
  the lone preposition ("from") to all verbs ("acquire", "authorize" and
  "deliver").  In other words, saying something like "Metadata
  properties describe how to acquire content from a downstream CDN,
  authorize a downstream CDN and deliver content to a downstream CDN."

- S3, first pargraph: s/content delivered for that Hostname/content
  delivered to that Hostname/

- S3.1, third paragraph: s/As well as/Besides/

- S3.1, Figure 1: The "Key" at the bottom left of the figure appears
  to be redundant; you have already described the symbols above
  (on top left).  Similarly, Table 1 does not add much beyond what
  is implicit in Figure 1; you can remove Table 1 without impacting
  anything (I believe).

- S3.1, Table 2: May be helpful to provide an example for "PathMatch".
  I found the examples in other definitions to be very useful.

  Ditto for "GenericMetaData".

- S3.2, first paragraph: Not sure what you mean by "opaque Metadata
  distribution".  If this is a term that is well known in the domain,
  you can leave it as such, if not, then expanding what this means
  may be useful.  Reading the rest of the section it appears that
  you are treating the properties that the dCDN does not understand
  as "opaque".  My suggestion would be to just
  s/and opaque Metadata distribution/and Metadata distribution/
  since the text in the rest of the section demonstrates what can
  be distributed and what is not subject to distribution.

- S4.1.6: How rigorous is the PatternMatch object?  Is the full regexp
  grammar permitted or only the subset shown in the section is allowed?
  Right now, the wording is ambiguous.  The patter may contain the
  wildcards, but are ranges allowed (as an example)?  I cannot tell
  from the current text.

- S4.2.2.1: What is a "Location object"?  I cannot find it in the
  Terminology section of this document nor can I find it in rfc6707.

- S4.2.3.1: You may want to consider putting a forward reference
  to the definition of TimeWindow objects here.

- S6, first/second paragraphs: Any specific reason why you changed
  from "dCDN" to "Downstream CDN" and from "uCDN" to "Upstream CDN"?
  While doing so is okay, it is better to retain one of these
  for uniformity throught the manuscript.

- S6.2, paragraph four: I suspect the mechanisms of dCDN decision are
  not subject to standardization (or out of scope)?  If so, may be
  a good idea to simply state this.

- S6.4.1, Table 3: Any specific reason why the syntax name suffix
  (+json, c.f. rfc6838, Section 4.2.8) is omitted from the MIME types
  defined in the table?  You do use the suffix in examples later.

- S6.4.2.1: The text at the bottom of page 29
  s/fetch from the next/fetch the next/

- S6.5: Seems to me that you are best moving steps 1-5 to the IANA
  Considerations (S7) since it overlaps with what is currently in
  the IANA Consideration section.  In S6.5, simply state that "Any
  document that defines a new GenericMetadata object MUST follow the
  steps outlined in Section 7 (IANA Considerations)."

- S6.6, end of the first paragraph: A spurious ':' perhaps?

Cheers,

- vijay
-- 
Vijay K. Gurbani, Bell Laboratories, Alcatel-Lucent
1960 Lucent Lane, Rm. 9C-533, Naperville, Illinois 60563 (USA)
Email: vkg@{bell-labs.com,acm.org} / [email-masked]
Web: http://ect.bell-labs.com/who/vkg/  | Calendar: http://goo.gl/x3Ogq

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From: "Francois Le Faucheur (flefauch)" <[email-masked]>
Date: Thu, 2 Jan 2014 18:29:26 +0000

Hi Vijay,

Thanks for following up on your commitment and doing the review. 

Francois

On 2 Jan 2014, at 19:05, "Vijay K. Gurbani" <[email-masked]>
 wrote:

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