Building Power-Efficient Constrained Application Protocol (CoAP) Devices for Cellular Networks
draft-ietf-lwig-cellular-06

[Ballot comment]
I share the comments about figure 1.

-- 3, radio technology:
Can you elaborate on the meaning of "bundling applications together"? Does it mean bundling the messages together for multiple applications? Something else?

-- 7: "If sub-second response time is not
  needed, a slightly more infrequent checking process may save some
  power."
Perhaps more than slightly?

-- 7, paragraph 3:
Is the "device" in the 4th sentence the same as the "sensor"?

[Ballot comment]
Nice work.

I had a couple of thoughts while reading through it.

This is a very useful draft. Thank you for producing it.

You mention the difficulty of acting as a server behind a NAT. I wonder if you might also mention the power drain that's often required to maintain port bindings on NATs when a device is not actively transmitting. That may not be a problem for sleepy devices, but might be for real-time reachable devices.

In this text

Manufacturer Server

      The DNS name of the directory or proxy is hardwired to the
      software by the manufacturer, and the directory or proxy is
      actually run by the manufacturer.  This approach is suitable in
      many consumer usage scenarios, where it would be unreasonable to
      assume that the consumer runs any specific network services.  The
      manufacturer's web interface and the directory/proxy servers can
      co-operate to provide the desired functionality to the end user.
      For instance, the end user can register a device identity in the
      manufacturer's web interface and ask specific actions to be taken
      when the device does something.

  Delegating Manufacturer Server

      The DNS name of the directory or proxy is hardwired to the
      software by the manufacturer, but this directory or proxy merely
      redirects the request to a directory or proxy run by the whoever
      bought the device.  This approach is suitable in many enterprise
      environments, as it allows the enterprise to be in charge of
      actual data collection and device registries; only the initial
      bootstrap goes through the manufacturer.  In many cases there are
      even legal requirements (such as EU privacy laws) that prevent
      providing unnecessary information to third parties.
     
The reference to legal requirements under "Delegating Manufacturer Server" made me think this was only appliable to "Delegating Manufacturer Server", but not to "Manufacturer Server". Is that the case? Or is it applicable whether the Manufacturer Server is delegating or not?

I share Stephen's comment on Figure 1.

[Ballot comment]


- intro: is CoAP really "point-to-point"? not sure that is a
good term to use here. I get what you mean when I get to the
end of page 6 though, but I still don't like the term as used
here.

- figure 1 doesn't tell me much to be honest, I'd say delete it
maybe or add some more text saying what it's there for.

- p6, proxies are provided for http yes, but why would they be
needed for coap? coap devices are not rendering html so don't
have a need for loads of DNS names/pictures/ads. I think that's
in the end a misleading conparison to make and would be better
omitted. (BTW, I don't mean you're trying to mislead, but  that
that comparison is likely to mislead the reader into thinking
they may get more from coap proxies than is the case.)

- p7, at end of section 3, you could (if you wanted), make the
point that "higher" layer network protocols like a DTN protocol
such as the BP could help (if deployed widely) as then
applications wouldn't assume that what they send is (almost)
immediately received. More practically, applications can
re-invent DTN functionality and get some of those benefits.

- section 5, I think it'd be worth noting that there is a need
for (but no good solution for) discovery of devices that are
manufactured by small manufs (or open source) and deployed in
small numbers. That is not the same as when a large vendor is
involved but would be worth noting.

- section 9: large numbers of esp. small battery powered
devices scattered everywhere are a significant polution threat.
(When not gathered at end of life.) That arguably ought be
noted as a reason to spend more on e.g.  PoE devices sometimes
- the overall environmental or carbon cost can be lower in the
end with a device that uses more power per hour.

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-lwig-cellular-04, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any IANA actions.

While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, IANA does not object.

If this assessment is not accurate, please respond as soon as possible.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Building Power-Efficient CoAP Devices for Cellular Networks) to Informational RFC


The IESG has received a request from the Light-Weight Implementation
Guidance WG (lwig) to consider the following document:
- 'Building Power-Efficient CoAP Devices for Cellular Networks'
  as Informational RFC

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf@ietf.org mailing lists by 2015-08-24. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract


  This memo discusses the use of the Constrained Application Protocol
  (CoAP) protocol in building sensors and other devices that employ
  cellular networks as a communications medium.  Building communicating
  devices that employ these networks is obviously well known, but this
  memo focuses specifically on techniques necessary to minimize power
  consumption.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-lwig-cellular/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-lwig-cellular/ballot/


No IPR declarations have been submitted directly on this I-D.

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?


i) Type of RFC Requested: Informational
ii) It is the proper type of RFC because the document is a memorandum discussing techniques for minimizing power consumption in devices using CoAP in cellular networks.
iii) The type of RFC is indicated in the title page header


(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.


The document discusses the use of the Constrained Application Protocol (CoAP) protocol in devices that employ cellular networks as a communications medium, with a specific focus on techniques necessary to minimize power consumption.


Working Group Summary:

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?


Nothing of significance.


Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?


The document does not specify a protocol therefore the question regarding protocol implementation does not apply. There as an implication that there has been some implementation experience leading to the guidelines in the document but it is not explicitly stated thus.


Personnel:

Who is the Document Shepherd? Who is the Responsible Area Director?


The Document Shepherd is Robert Cragie. The Responsible Area Director is Brian Haberman.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.


The Document Shepherd has thoroughly reviewed through the document and considers it ready for publication.


(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?


The document has been submitted for review on the lwig WG mailing lists and has had a small amount of discussion. Feedback comments have been incorporated.


(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.


The Document Shepherd does not consider that the document requires review from a broader perspective.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.


The Document Shepherd has no specific concerns or issues with the document.


(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?


The authors have confirmed that there are no IPR disclosures required for full conformance with BCP 78 and BCP 79.


(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.


There are no IPR disclosures that reference the document.


(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?


It has been discussed in recent meetings and on the mailing list therefore the conclusion is that the WG as a while understands and agrees with the document.


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)


No.


(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.


There are no error and no warnings from a verbose nits check of draft-04. There is one obsolete reference (RFC 4627 (Obsoleted by RFC 7159)).


(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, media type, and URI type reviews.


No formal review required.


(13) Have all references within this document been identified as either normative or informative?


Yes.


(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?


All normative references are in a clear state.


(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.


No.


(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.


The publication of this document will not affect the status of any existing RFCs.


(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 5226).


There are no IANA considerations.


(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.


None.


(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, etc.


There are no parts of the document written in a formal language.