Content Delivery Network Interconnection (CDNI) Control Interface / Triggers
draft-ietf-cdni-control-triggers-15

[Ballot comment]
Thanks for handling my DISCUSS point related to the TLS requirement.  I had one remaining DISCUSS point that I am not sure has been resolved--but after the conversation that did happen, it is probably no longer DISCUSS-worthy:

- 4.7, 2nd bullet under handling of offline surrogates:

I assume I am missing something here. How does a surrogate know that the situation exists in the first place? How would a surrogate know about invalidate commands that happened while it was offline?
-------------

The remaining comments are old. I think they've mostly been addressed, but did not recheck them:

- 3, paragraph 5:
SHOULD should not be equated with "optional to implement". MAY means that. SHOULD is intended to be stronger.

- 4.5, 2nd paragraph, 1st sentence:
This is pretty convoluted. I suggest reformulating without the past tense "MUST". For example, "The dCNI MUST report the expiration times if..."

-4.6: "If CDNs B and C delegate delivery of CDN A’s content to each other"
Is this a reasonable configuration? It seems like they might already have a delegation loop before the trigger interface got involved.
Also, the first sentence is a fragment.

= 4.8, first paragraph:
I suggest s/transform/"similarly transform"

- 5.1.3, staleresourcetime, mandatory:
Doesn't this effectively mean the value must be the same across all collections?

- 5.2.1, content.ccid:
Seems like the reference to [I-D.ietf-cdni-metadata] should be normative.

- 6.2.5:
it looks like the dCDN is sending the request to itself. Is that the intent?

- 8.1, last paragraph: "In this case, the dCDN MUST allow each uCDN from which the content could have been acquired to act upon that content using CI/T Commands."
This seems like a place where local policy might reasonably vary. Is a MUST really appropriate?

[Ballot comment]
Thank you for addressing my earlier comments.

Regarding my earlier change: Media type: should it have +json suffix? Is the currently defined media type deployed?

-- I didn't realize that application/cdni is already registered with IANA by RFC 7736. So this comment doesn't apply and should revert this change. I am sorry about that!

[Ballot comment]
Below is my AD review. I am sorry if my comments are a bit cryptic, feel free to ask for clarifying questions.

First mention of HTTP, its methods or response codes needs to have a reference to RFC 7230. This applies to section 2.
Similarly, the first reference to URL should clarify that you only mean http/https URLs and use RFC 7230 as well.

In 4.1, at the bottom of page 10: "dCDN SHOULD track and report..." - how?

In 4.6: a normative reference that defines AS (RFC 1930?) is needed here.

How are client and server identities verified during mutual TLS authentications?

In 5.2.2: is the list of trigger types extensible? If yes, does it need an IANA registry?

Similar: 5.2.7 (error types). I suspect the answer is yes here.

Media type: should it have +json suffix? Is the currently defined media type deployed?


At the bottom of page 34 there is the following text:

When the CI/T Trigger Command is complete, the contents of the
filtered collections will be updated along with their Entity Tags.
For example, when the two example CI/T Trigger Commands are complete,
the collections of pending and complete Trigger Status Resources
might look like:

after that there are 2 examples on pages 35 and 36, both with URI
"/triggers/complete". I think one of the should be " /triggers/pending,
I think it is the one on page 35.

[Ballot comment]
Below is my AD review. I am sorry if my comments are a bit cryptic, feel free to ask for clarifying questions.

First mention of HTTP, its methods or response codes needs to have a reference to RFC 7230. This applies to section 2.
Similarly, the first reference to URL should clarify that you only mean http/https URLs and use RFC 7230 as well.

In Section 4 you are referencing generic HTTP without any version number and saying that any HTTP feature can be used. I think you really need to have at least a version number here, because I don't think you mean HTTP/2.0. Adding the above references probably makes this comment unimportant.

In 4.1, at the bottom of page 10: "dCDN SHOULD track and report..." - how?

In 4.6: a normative reference that defines AS is needed here.

How is HTTP Authentication done?

Does CBOR-CDDL reference needs to be Normative? While the Appendix is Informative, CBOR-CDDL need to be understood in order to interpret it.

In 5.2.2: is the list of trigger types extensible? If yes, does it need an IANA registry?

Similar: 5.2.7 (error types). I suspect the answer is yes here.

Media type: should it have +json suffix? Is the currently defined media type deployed?

On page 36 - should the URL include "pending", not "complete" (as per the description before this and the previous request/response).

[Ballot comment]

- I agree with the discuss points about use of TLS.

- I think it'd be better if you clarified that by
"mutually authenticated" you mean TLS client auth and
TLS server auth and not e.g. HTTP BASIC plus TLS server
auth.

- I think a statement to the effect that the mechanisms
for access control are dCDN-specific (for now at least)
might be a good addition. I'm guessing that someone
might want to use some form of OAuth later on (or is
doing so now) so part(s) of that might be a thing to
standardise later.

[Ballot discuss]
= Section 5.1.8 =

Name: staleresourcetime

        Description: The length of time for which the dCDN guarantees
        to keep a completed Trigger Status Resource.  After this time,
        the dCDN SHOULD delete the Trigger Status Resource and all
        references to it from collections.

I'm not clear on why this is a SHOULD rather than a MUST. If the dCDN tells the uCDN it's going to delete resources after a specified period of time, why shouldn't it follow through on that? For a uCDN that relies on resources not sticking around after a specified period of time (because of security or competitive concerns), doesn't this need to be a firm requirement so that the uCDN doesn't have to issue purge requests to be sure that its resources get deleted?

= Section 8.1 =

I had the same confusion as Ben and the secdir reviewer concerning whether TLS is always required to use or not. If there are cases in which TLS is not mandatory to use, then I think this should be phrased as a SHOULD with the exceptions clearly enumerated. For example, it's not clear to me whether the only exception is environments where equivalent protections are afforded by a different protocol, or if just being within a single administrative domain is considered protection enough (not sure I agree with the latter).

[Ballot comment]
= General =

I think the examples in the document should use https URIs.

= Section 3 =
"Trigger Status Resources belonging to a uCDN MUST NOT
  be visible to any other CDN.  The dCDN could, for example, achieve
  this by offering different collection URLs to each uCDN, and/or by
  filtering the response based on the uCDN with which the HTTP client
  is associated."

Using different URLs for different uCDNs is not sufficient for this, correct? I think the "and/or" needs to be just "and".

= Section 4.1 =
I don't understand the difference between when status is used in quotes and not in quotes, e.g., 'Once processing has started the "status" MUST be "active"' vs. 'once the CI/T Command is complete, the status MUST be set to "complete" or "failed"'.

= Section 4.3 =
s/requires no processing in the dCDN, its status MUST NOT be changed/requires no processing in the dCDN. Its status MUST NOT be changed/

= Section 5.1.1 =

"Name: cdn-path

        Description: The CDN Provider Identifiers of CDNs that have
        already accepted the CI/T Command."
       
I find the phrase "already accepted" somewhat confusing, since a uCDN is supposed to insert its own on ID here, and in that sense hasn't "accepted" anything, but is making the request itself.

= Section 8.3 =
s/parties other party than the authorised dCDN/parties other than the authorised dCDN/

[Ballot comment]
I'm a no objection, but do want to see why TLS is not a MUST.  I've responded to Ben's discuss that proposes language to make it clear whether or not TLS is a MUST.  Right now, I think it is just a MUST when certain conditions are met - the need for the security properties called out in 8.1 and commercial privacy considerations in 8.3.

[Ballot discuss]
I've got two concerns that I think  leave  ambiguity around important normative requirements. Hopefully they will be easy to resolve:

- 4.7, 2nd bullet under handling of offline surrogates:

I assume I am missing something here. How does a surrogate know that the situation exists in the first place? How would a surrogate know about invalidate commands that happened while it was offline?

- 8.1,  4th paragraph from the end:
The language here is ambiguous about whether the use of TLS is _always_ required, or just when "such protection is required." From context, I assume the latter to be the case. But "To that end..." can be interpreted to mean "In that case, one MUST do X", or to mean "In order to make that possible when needed, one MUST _always_ do X"

I propose the following:
OLD:
  In an environment where any such protection is required, mutually
  authenticated encrypted transport MUST be used to ensure
  confidentiality of the CI/T information.  To that end, TLS MUST be
  used by CI/T, including authentication of the remote end.
NEW:
  In an environment where any such protection is required, mutually
  authenticated and encrypted TLS MUST be used to ensure
  confidentiality of the CI/T information.
END.

[Ballot comment]
- 3, paragraph 5:
SHOULD should not be equated with "optional to implement". MAY means that. SHOULD is intended to be stronger.

- 4.5, 2nd paragraph, 1st sentence:
This is pretty convoluted. I suggest reformulating without the past tense "MUST". For example, "The dCNI MUST report the expiration times if..."

-4.6: "If CDNs B and C delegate delivery of CDN A’s content to each other"
Is this a reasonable configuration? It seems like they might already have a delegation loop before the trigger interface got involved.
Also, the first sentence is a fragment.

= 4.8, first paragraph:
I suggest s/transform/"similarly transform"

- 5.1.3, staleresourcetime, mandatory:
Doesn't this effectively mean the value must be the same across all collections?

- 5.2.1, content.ccid:
Seems like the reference to [I-D.ietf-cdni-metadata] should be normative.

- 6.2.5:
it looks like the dCDN is sending the request to itself. Is that the intent?

- 8.1, last paragraph: "In this case, the dCDN MUST allow each uCDN from which the content could have been acquired to act upon that content using CI/T Commands."
This seems like a place where local policy might reasonably vary. Is a MUST really appropriate?

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

IANA has completed its review of draft-ietf-cdni-control-triggers-11.txt. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there is a single action which IANA must complete.

In the CDNI Payload Types registry in the Content Delivery Networks Interconnection (CDNI) Parameters located at:

http://www.iana.org/assignments/cdni-parameters/

Three new payload types are to be registered as follows:

Payload Type: ci-trigger-command
Reference: [ RFC-to-be ]

Payload Type: ci-trigger-status
Reference: [ RFC-to-be ]

Payload Type: ci-trigger-collection
Reference: [ RFC-to-be ]

IANA Note --> As this document requests registrations in an Expert Review or Specification Required (see RFC 5226) registry, we will initiate the required Expert Review via a separate request. If there is no expert designated for the registry, we will work with the IESG to have one assigned. Expert review will need to be completed before your document can be approved for publication as an RFC.

IANA understands that this is the only action required to be completed upon approval of this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is only to confirm what actions will be performed. 

Thank you,

Sabrina Tanamal
IANA Specialist
ICANN

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: flefauch@cisco.com, cdni@ietf.org, draft-ietf-cdni-control-triggers@ietf.org, barryleiba@gmail.com, cdni-chairs@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (CDNI Control Interface / Triggers) to Proposed Standard

The IESG has received a request from the Content Delivery Networks
Interconnection WG (cdni) to consider the following document:
- 'CDNI Control Interface / Triggers'
  as Proposed Standard

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 2015-12-21. 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 document describes the part of the CDN Interconnection Control
  Interface that allows a CDN to trigger activity in an interconnected
  CDN that is configured to deliver content on its behalf.  The
  upstream CDN can use this mechanism to request that the downstream
  CDN pre-positions metadata or content, or that it invalidates or
  purges metadata or content.  The upstream CDN can monitor the status
  of activity that it has triggered in the downstream CDN.


Reviewers should note the following downward references (see RFC 3967):
- RFC 6707 is used as a reference for CDNI terminology.
- RFC 2818 is used as a reference for HTTP over TLS.


The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-cdni-control-triggers/

Once IESG discussion begins, it can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-cdni-control-triggers/ballot/

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

(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?

  This document requests the Proposed Standard track. This is
  appropriate given it defines a full CDNI interface. It 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

  This document describes the part of the CDN Interconnection Control
  Interface that allows a CDN to trigger activity in an interconnected
  CDN that is configured to deliver content on its behalf.  The
  upstream CDN can use this mechanism to request that the downstream
  CDN pre-positions metadata or content, or that it invalidates or
  purges metadata or content.  The upstream CDN can monitor the status
  of activity that it has triggered in the downstream CDN.

Working Group Summary

  There is a strong consensus in support of this document.

Document Quality

  The document is well written and of good quality. It has been
  reviewed by multiple active members of the working group. It has also
  been through an early Appsdir review, with specific focus on JSON
  specification and HTTP.

Personnel

  Document Shepherd: Francois Le Faucheur
  Responsible Area Director: Barry Leiba

(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 shepherd did a review of an earlier version of the document and
  there has only small changes since. The shepherd feels the document
  is ready for publication.

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

  The shepherd does not have concerns about the level of reviews performed.


(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 needed review by JSON experts, but this review has
  already been conducted as part of an early AppsDir review (Carsten
  Bormann).


(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 shepherd does not have any concern or issue with this 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 two authors have explicitly confirmed the above.

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

  No IPR disclosure have been filed referencing that 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? 

  There is strong consensus in the working group on this document. It
  has been discussed clearly with many supporting the corresponding
  approach and none objecting to it.


(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 one has threaten to appeal. In fact noone has even objected.

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

  There is no remaining ID nits.


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

  The document was subject to a JSON expert review by Carsten Bormann.
  The document no longer defines any media-type, since it now simply
  uses the single CDNI Media Type specified in
  draft-ietf-cdni-media-type that has already been reviewed and
  approved by the IESG.


(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 already RFC.

(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.

  There are no downward references.


(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.

  Publication of this document will not change the status of any
  document. This is correctly identified in the title page header.

(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).

  This document defines entries in an IANA registry that was created by
  draft-ietf-cdni-media-type that has already been reviewed and
  approved by the IESG.  The entries defined in the registry match what
  is used in the body of the document.


(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.

  The document does not define any new registry.


(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.

  This is not applicable.

(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?

    This document requests the Proposed Standard track. This is appropriate given it defines a full CDNI interface. It 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

  This document describes the part of the CDN Interconnection Control
  Interface that allows a CDN to trigger activity in an interconnected
  CDN that is configured to deliver content on its behalf.  The
  upstream CDN can use this mechanism to request that the downstream
  CDN pre-positions metadata or content, or that it invalidates or
  purges metadata or content.  The upstream CDN can monitor the status
  of activity that it has triggered in the downstream CDN.

Working Group Summary

  There is a strong consensus in support of this document.

Document Quality

  The document is well written and of good quality. It has been reviewed by multiple active members of the working group. It has also been through an early Appsdir review, with specific focus on JSON specification and HTTP.

Personnel

  Document Shepherd: Francois Le Faucheur
  Responsible Area Director: Barry Leiba

(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 shepherd did a review of an earlier version of the document and there has only small changes since. The shepherd feels the document is ready for publication.

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

    The shepherd does not have concerns about the level of reviews performed.


(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 needed review by JSON experts, but this review has already been conducted as part of an early AppsDir review (Carsten Bormann).


(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 shepherd does not have any concern or issue with this 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 two authors have explicitly confirmed the above.

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

    No IPR disclosure have been filed referencing that 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? 

    There is strong consensus in the working group on this document. It has been discussed clearly with many supporting the corresponding approach and none objecting to it.


(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.)

  Noone has threaten to appeal. In fact noone has even objected.

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

    There is no remaining ID nits.


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

    The document was subject to a JSON expert review by Carsten Bormann. The document no longer defines any media-type, since it now simply uses the single CDNI Media Type specified in draft-ietf-cdni-media-type that has already been reviewed and approved by the IESG.


(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 already RFC.

(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.

    There are no downward reference


(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.

  Publication of this document will not change the status of any document. This is correctly identified in the title page header.

(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).

    This document defines entries in an IANA registry that was created by draft-ietf-cdni-media-type that has already been reviewed and approved by the IESG.  The entries defined in the registry match what is used in the body of the document.


(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.

  The document does not define any new registry.


(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.

  This is not applicable