Telechat Review of draft-ietf-core-cocoa-03

Request Review of draft-ietf-core-cocoa
Requested rev. no specific revision (document currently at 03)
Type Telechat Review
Team General Area Review Team (Gen-ART) (genart)
Deadline 2018-04-03
Requested 2018-02-22
Authors Carsten Bormann, August Betzler, Carles Gomez, Ilker Demirkol
Draft last updated 2018-03-16
Completed reviews Tsvart Early review of -02 by Wesley Eddy (diff)
Opsdir Telechat review of -02 by Scott Bradner (diff)
Secdir Telechat review of -03 by Vincent Roca
Opsdir Telechat review of -03 by Scott Bradner
Tsvart Telechat review of -03 by Wesley Eddy
Genart Telechat review of -03 by Christer Holmberg
Assignment Reviewer Christer Holmberg
State Completed
Review review-ietf-core-cocoa-03-genart-telechat-holmberg-2018-03-16
Reviewed rev. 03
Review result Ready with Issues
Review completed: 2018-03-16


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Document: draft-ietf-core-cocoa-03
Reviewer: Christer Holmberg
Review Date: 2018-03-16
IETF LC End Date: None
IESG Telechat date: 2018-04-05


From a technical perspective I don’t have any issues. However, I think the document could use quite a bit of editorial improvements. There is lots of inconsistent terminology, “speech-to-text” etc. I will focus on parts that I think are unclear.

Major issues: N/A

Minor issues: N/A

Nits/editorial comments: 



The document uses lots of different, and often complicated, terminology for referencing RFC 7252.


“In the definition of the CoAP protocol [RFC7252],…”

“The CoRE CoAP specification defines…”

Etc etc.

Please use consistent terminology. I suggest to simply say “CoAP [RFC7252]” or “[RFC7252]”. 



In some places the text says:

“The present specification…”

I suggest to say:

“This specification…”



The draft uses “CoAP endpoint” and “endpoint” terminology. Please use consistent terminology.



The draft uses “RTO estimator” and “estimator” terminology. Please use consistent terminology.

Also, what is an “RTO estimator”?



Some of the sections are named “Discussion”. However, they still contain normative procedures, and even RFC2119 terminology (MUST, SHOULD etc). Because of that, I think it is more than a discussion. A discussion is typically used to justify something, or to give some background, not to define procedures.


The Abstract and the Introduction say:

   “CoAP, the Constrained Application Protocol, needs to be implemented
   in such a way that it does not cause persistent congestion on the
   network it uses.”

What exactly does this mean? Implemented in what way?


The text in Section 2 says:

   “The present specification is based on the approved text in the [RFC7252] base specification.”

I don’t understand the “approved” part. Since RFC 7252 has been published, I assume the text is approved :)


The text in Section 3 refers to “Responder”. However, it is not defined/referenced anywhere.


The text in Section 4.3 says:

“The state of the RTO estimators for an endpoint SHOULD be kept as long as possible.”

Later the text says that the RTO state depends on whether there is other state (DTLS etc) or not? Can the sentence above be removed?


The text in Section 4.3 says “very strongly RECOMMENDED” and “strongly RECOMMENDED”. That sounds like a “SHOULD” in my ears :)


The text in Section 4.3 talks about “State of RTO estimator” and “RTO state”. Are these different states?


The text in Section 5 talks about “non-confirmables”. Please include a reference or definition.


The text in Section 7 says:

   “The security considerations of, e.g., [RFC5681], [RFC2914], and
   [RFC8085] apply.  Some issues are already discussed in the security
   considerations of [RFC7252].”

I don’t think you can say “e.g.,” and “Some issues”. It needs to be clear which security considerations apply.