JavaScript Session Establishment Protocol (JSEP)
draft-ietf-rtcweb-jsep-26

[Ballot comment]
I found myself wishing that Section 3.8 was a bit clearer about the advantages of sequential versus parallel forking. I can imagine some of the advantages because I have a SIP background, and I can dig some of what I was expecting to see in 3.8.2, but I'm imagining and digging, and I'm betting that the document could be more explicit about the tradeoffs - just saying "if you're communicating with a SIP endpoint, most of them can only exchange media with one endpoint at a time" is already helping.

[Ballot comment]
I think that this is a well-written document -- while reading through the Directorate reviews the last line of PHB's SecDir comment made me laugh.

[Ballot comment]
I'm sure the RFC editor would have caught this nit:

2nd paragraph of security considerations section:
While formally the JSEP interface is an API, it is better to think of
  it is an Internet protocol
s/is an Internet/as an Internet/

[Ballot comment]
I'm balloting "yes", but I have some minor comments and nits:

Substantive:

- General:
I still find the edges around where SDP is and isn't required a bit vague. Section 3.3 says that the JSEP implementation internal representation is SDP. While I have trouble imagining implementing this otherwise, do we really mean to mandate the internals? Is there an assumption that said internal representation is _serialized_ SDP vs some abstract internal representation?

Section 3.1 says that the signaling model is not specified. Is there an implicit assumption that, however things are signaled, the signaling process moves around serialized SDP? Or is it envisioned that one could write an application without serialized SDP occurring anywhere above the API?

-5, throughout: There are a number of normative keywords used in constructions like "... MUST foo, as described in RFCXXX". That construction is ambiguous about whether it defines a normative requirement to do something, and the doing of that something is described in the RFC, or if describes the referenced RFC as defining the MUST.

In general, it's best to avoid using 2119/8174 keywords to talk about external requirements, except as a direct quote. I think this is especially true here given the interdependencies between drafts in cluster 238. If in the future we update a dependency to change a normative requirement, we risk creating conflicts, and we make it unclear which text is authoritative.

-5.1.1: I think the operative requirement is "MUST support" rather than "MUST indicate support". (While indication may also be required, it seems a consequence of "MUST support".)

-5.1.2: " Any profile in the offer matching one of the following MUST be accepted:"
Isn't the real requirement that any of the following must be interpreted the same, or otherwise in some specified way? I assume there may be completely unrelated reasons to reject an m-section, but the "MUST be accepted" language seems to overrule that.

-5.4: "The SDP returned from createOffer or createAnswer MUST NOT be changed
  before passing it to setLocalDescription."
Is that a requirement on the JSEP implementation, or the javascript application? If the latter, is it appropriate to put normative requirements on the application? It seems like it would be better to normatively state the JSEP implementations's behavior when the application does something incorrect.  (Which seems to be done further down the page.)

-5.7: " The effect of rollback MUST be the same regardless of whether setLocalDescription or setRemoteDescription is called."
Does that mean if I call setLocalDescription, then rollback with a call to setRemoteDescription, _both_ are rolled back?

-5.8.3: The MUSTs in this section seem to be putting requirements on the SDP being parsed. Shouldn't they instead describe the parser's behavior based on that SDP input? The correctness of the SDP being parsed seems beyond the control of the implementation.

-8, second paragraph: When describing how the javascript is untrusted, it may be worth mentioning that it may have been downloaded from an untrusted source.

Editorial and Nits:

-1.1: Please expand ICE and MCU on the first mention.
s/config/configuration
Sentence starting with "Through its abstraction of signaling...": Should that say "Though it abstracts signaling..."

-2: Please consider using the boilerplate from RFC 8174. There are a number of instances of lowercase versions of normative keywords.

-3.2, paragraph 2: The MUST seems like a statement of fact.

-3.4.1, 2nd paragraph: Please expand or explain "mid" on first mention. (It is explained 3.5.2.1)

-3.5.1, last paragraph: Inconsistent capitalization: "MID"

-3.5.2.1: Please expand (or define) "ufrag" on first mention.

-3.6.1, first paragraph: is "intersect" the correct verb here? Missing conjunction in "hardware decoder capababilities, local policy".

-3.6.2, 2nd paragraph: s/"may be producing"/"may produce"

-4.1.2: Please expand LS on first mention. (I can guess from context. Please don't make me :-)  )

- 4.1.6: s/"codec/RTP/RTCP"/"codec, RTC, or RTCP"
"for each SDP line, the generation of the SDP will follow the process defined for generating an initial offer from the document that specifies the given SDP line."
While I worked out what that means, I found "document" to be ambiguous. At first I interpreted it as the "SDP document" rather than "the RFC". (Note this occurs several times in subsequent sections.)

-4.1.8, third paragraph: ""pranswer" indicates that a description should be parsed as an
  answer, but not a final answer"
I think it would be more clear to say "... parsed as a provisional answer, rather than a final answer".

-5.2.1: Paragraph starting with: " Each m= section, provided it is not marked as bundle-only, MUST generate..."
The m= section is not the real actor here, is it?

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

The IANA Services Operator has reviewed draft-ietf-rtcweb-jsep-21, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any registry 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, we do not object.

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

Thank you,

Sabrina Tanamal
IANA Services Specialist

The following Last Call announcement was sent out (ends 2017-08-11):

From: The IESG
To: IETF-Announce
CC: draft-ietf-rtcweb-jsep@ietf.org, ted.ietf@gmail.com, adam@nostrum.com, rtcweb-chairs@ietf.org, Ted Hardie , rtcweb@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (JavaScript Session Establishment Protocol) to Proposed Standard


The IESG has received a request from the Real-Time Communication in
WEB-browsers WG (rtcweb) to consider the following document: - 'JavaScript
Session Establishment Protocol'
  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 2017-08-11. 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 mechanisms for allowing a JavaScript
  application to control the signaling plane of a multimedia session
  via the interface specified in the W3C RTCPeerConnection API, and
  discusses how this relates to existing signaling protocols.




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

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-rtcweb-jsep/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?

This document is intended for Proposed Standard, as is appropriate for a consensus protocol specification of an IETF working group.  The document indicates that it is standards track on the title page.

(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 mechanisms for allowing a Javascript
  application to control the signaling plane of a multimedia session
  via the interface specified in the W3C RTCPeerConnection API and
  relates this signaling to the media streams and data channels which
  are created and managed by the application.

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?

The working group process leading up to this document was
quite long and required unusual levels of coordination with
the group producing the API and the groups responsible for the
underlying mechanisms (especially those responsible for SDP,
ICE, and RTP).  During the process there were some decisions
which moved between groups in ways that made consensus
difficult to judge because the groups were not  completely
congruent.  As document shepherd, I believe that the issues
which remain in this document have consensus. 

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?

There are existing implementations of this protocol in two of
those most popular web browsers and in many hundreds of applications. 

Those who contributed significant text and reviews are mentioned in
the acknowledgements section.


Personnel

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

Ted Hardie is the document shepherd.  Adam Roach is the responsible area director.

(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.

This document was maintained by its authors using a Github repository and the issues
raised for the document were tracked using issues and pull requests, as is typical for
that method.  I have reviewed the issues raised against the previous versions of this
document and I have confirmed that this version addresses those.

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

I have no serious concerns.  As noted above, this document has been in development
for a significant period of time and there has been attrition in the working group as
it neared a conclusion.  The two working group last calls did, however, produce significant
reviews by the working group participants who are both familiar with the subject
matter and IETF specifications.  (e.g. by Bernard Aboba and Magnus Westerlund).

(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 uses of SDP did require such review, and Paul Kyzivat and Magnus Westerlund
supplied it along with Bernard Aboba and others; some of the novel uses required
work from other groups, such as MMUSIC, and were progressed as separate specifications
there (e.g. BUNDLE).

(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.

I note that there are examples in this document and in a separate
working group document as well ( draft-ietf-rtcweb-sdp).  This split
was decided by the working group some time ago so that SDP relevant
to non-mandatory codecs and features could be well described.  The examples
were produced by overlapping teams but are nonetheless stylistically different,
and there is some potential for confusion there.  The working group will
address this in the context of draft-ietf-rtcweb-sdp, however, so I do not believe
this is blocking for this core specification. 

An issue was raised about which version of the ICE specification was appropriate
to reference.  The chairs and Area Director agreed to go forward with the current
specification and to revisit with the RFC editor during the publication of cluster
238, as there are no dependencies in this specification on features specific to ICEbis.

(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.

They have confirmed conformance.

(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 disclosures have been filed.

(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? 

The WG consensus behind this document is solid.  It has been a long time in development, so there is some exhaustion, but the continued engagement is high enough to demonstrate that it is not simply an author 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.)

I am not aware of any appeals likely on this document.

(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.

None identified.

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

This document makes no requests of IANA and has no new URIs, media types,
YANG models, or MIBs.

(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?

This document is part of cluster 238, and I believe the IESG and the RFC editor staff
are aware of  the set of documents which will emerge when it is unstuck.

(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 a total of 18 documents in the normative category which are Internet-Drafts,
but the working group is not requesting that these be processed using the downref
procedure.

(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.

This document will not change 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).

This document makes no requests of IANA.

(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.

This document makes no requests of IANA.


(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.

As noted above, the SDP constructions were checked by expert review.

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?

This document is intended for Proposed Standard, as is appropriate for a consensus protocol specification of an IETF working group.  The document indicates that it is standards track on the title page.

(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 mechanisms for allowing a Javascript
  application to control the signaling plane of a multimedia session
  via the interface specified in the W3C RTCPeerConnection API and
  relates this signaling to the media streams and data channels which
  are created and managed by the application.

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?

The working group process leading up to this document was
quite long and required unusual levels of coordination with
the group producing the API and the groups responsible for the
underlying mechanisms (especially those responsible for SDP,
ICE, and RTP).  During the process there were some decisions
which moved between groups in ways that made consensus
difficult to judge because the groups were not  completely
congruent.  As document shepherd, I believe that the issues
which remain in this document have consensus.

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?

There are existing implementations of this protocol in two of
those most popular web browsers and in many hundreds of applications. 

Those who contributed significant text and reviews are mentioned in
the acknowledgements section.


Personnel

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

Ted Hardie is the document shepherd.  Adam Roach is the responsible area director.

(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.

This document was maintained by its authors using a Github repository and the issues
raised for the document were tracked using issues and pull requests, as is typical for
that method.  I have reviewed the issues raised against the previous versions of this
document and I have confirmed that this version addresses those.

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

I have no serious concerns.  As noted above, this document has been in development
for a significant period of time and there has been attrition in the working group as
it neared a conclusion.  The two working group last calls did, however, produce significant
reviews by the working group participants who are both familiar with the subject
matter and IETF specifications.  (e.g. by Bernard Aboba and Magnus Westerlund).

(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 uses of SDP did require such review, and Paul Kyzivat and Magnus Westerlund
supplied it along with Bernard Aboba and others; some of the novel uses required
work from other groups, such as MMUSIC, and were progressed as separate specifications
there (e.g. BUNDLE).

(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.

I note that there are examples in this document and in a separate
working group document as well ( draft-ietf-rtcweb-sdp).  This split
was decided by the working group some time ago so that SDP relevant
to non-mandatory codecs and features could be well described.  The examples
were produced by overlapping teams but are nonetheless stylistically different,
and there is some potential for confusion there.  The working group will
address this in the context of draft-ietf-rtcweb-sdp, however, so I do not believe
this is blocking for this core specification.

(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.

They have confirmed conformance.

(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 disclosures have been filed.

(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? 

The WG consensus behind this document is solid.  It has been a long time in development, so there is some exhaustion, but the continued engagement is high enough to demonstrate that it is not simply an author 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.)

I am not aware of any appeals likely on this document.

(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.

None identified.

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

This document makes no requests of IANA and has no new URIs, media types,
YANG models, or MIBs.

(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?

This document is part of cluster 238, and I believe the IESG and the RFC editor staff
are aware of  the set of documents which will emerge when it is unstuck.

(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 a total of 18 documents in the normative category which are Internet-Drafts,
but the working group is not requesting that these be processed using the downref
procedure.

(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.

This document will not change 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).

This document makes no requests of IANA.

(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.

This document makes no requests of IANA.


(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.

As noted above, the SDP constructions were checked by expert review.