The Session Description Protocol (SDP) WebSocket Connection URI Attribute
RFC 8124

Received changes through RFC Editor sync (created alias RFC 8124, changed title to 'The Session Description Protocol (SDP) WebSocket Connection URI Attribute', changed abstract to 'The WebSocket protocol enables bidirectional real-time communication between clients and servers in web-based applications.  This document specifies extensions to Session Description Protocol (SDP) for application protocols using WebSocket as a transport.', changed pages to 12, changed standardization level to Proposed Standard, changed state to RFC, added RFC published event at 2017-03-30, changed IESG state to RFC Published)

[Ballot comment]
How does this interact with websocket sub-protocol specifications? Is there an expectation one might take some existing media protocol and use it with this draft _without_ a sub-protocol spec? I note the examples use bfcp, which in fact has a sub-protocol spec on this same telechat. (Most of my detailed comments are related to this)

- 4.2, first paragraph: Am I correct that the "proto" field would also include the sub-protocol? (e.g. TCP/WSS/BFCP)? Would you ever have a "proto" filed value of just "TCP/WS(S)?

- 4.2, 2nd paragraph
I wonder if the guidance here (the recommendation that the offerer is the active party) doesn't vary by sub-protocol? Or if it doesn't, if it's more a matter of topology (e.g. servers with global IP addresses vs clients behind NATs) than a matter of who sends the offer?
Also, please consider citing 4145 in this paragraph. (You do in 4.3).

[Ballot comment]
I may have missed it, but don't see a clear reason (would expect to see it in the security considerations section) as to why TLS isn't a MUST.  RECOMMENDED is good, but having a reason to justify this would be helpful.  It seems like it is for legacy support of HTTP applications, but spelling that out might be helpful.

[Ballot comment]
- sec 4.2. The MUST here is inappropriate (given the split of docs):
„For example, to negotiate BFCP-over-WebSocket the "proto" value in the
  "m=" line MUST be TCP/WSS/BFCP if WebSocket is over TLS, else it MUST
  be TCP/WS/BFCP.“
Should be instead:
„For example, to negotiate BFCP-over-WebSocket the "proto" value in the
  "m=" line is TCP/WSS/BFCP if WebSocket is over TLS, else it is
  TCP/WS/BFCP., as specified in [I-D.ietf-bfcpbis-bfcp-websocket]“
- Also remove the following sentence in section 4.3:

„For BFCP application, the "proto" value in the "m=" line
  MUST be TCP/WSS/BFCP if WebSocket is run on TLS, else it MUST be
  TCP/WS/BFCP.“
- In section 6: „a=ws/a=wss-uri“. Maybe use „a=ws-uri/a=wss-uri“ instead?

[Ballot discuss]
This is generally a well written document, but I have a small list of issues that I would like to discuss before recommending its approval:

1) Are a=ws-uri and a=wss-uri mutually exclusive? (Section 4.3 is a good place to mention what to do if both are specified).

Why not a single attribute, considering that both ws: and wss: URIs are possible?

2) In Section 6: how is Websocket TLS server identity verified?

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

The IANA Services Operator has completed its review of draft-ietf-bfcpbis-sdp-ws-uri-07.txt. If any part of this review is inaccurate, please let us know.

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

In the att-field (media level only) subregistry of the Session Description Protocol (SDP) Parameters registry located at:

https://www.iana.org/assignments/sdp-parameters/

two new entries are to be added as follows:

Type: att-field (media level only)
SDP Name: ws-uri
Mux Category: CAUTION
Reference: [ RFC-to-be ]

Type: att-field (media level only)
SDP Name: wss-uri
Mux Category: CAUTION
Reference: [ RFC-to-be ]

Because this registry requires Expert Review [RFC5226] for registration, we've contacted the IESG-designated expert in a separate ticket to request approval. Expert review should be completed before your document can be approved for publication as an RFC.

The IANA Services Operator 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 Services Specialist
PTI

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: draft-ietf-bfcpbis-sdp-ws-uri@ietf.org, "Charles Eckel" , bfcpbis-chairs@ietf.org, bfcpbis@ietf.org, alissa@cooperw.in, eckelcu@cisco.com
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Session Description Protocol (SDP) WebSocket Connection URI Attribute) to Proposed Standard


The IESG has received a request from the Binary Floor Control Protocol
Bis  WG (bfcpbis) to consider the following document:
- 'Session Description Protocol (SDP) WebSocket Connection URI
Attribute'
  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 2017-01-12. 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


  The WebSocket protocol enables bidirectional real-time communication
  between clients and servers in web-based applications.  This document
  specifies extensions to Session Description Protocol (SDP) for
  application protocols using WebSocket as a transport.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-bfcpbis-sdp-ws-uri/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-bfcpbis-sdp-ws-uri/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?

Proposed Standard. The title page has an intended status of "Standards Track".

(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:
The WebSocket [RFC6455] protocol enables two-way message exchange between clients and servers on top of a persistent TCP connection, optionally secured with Transport Layer Security (TLS) [RFC5246].  The WebSocket protocol was designed for, and is typically used in, web-based applications. This document specifies extensions to Session Description Protocol (SDP) for application protocols using WebSocket as a transport.

Working Group Summary:
This document was created as a result of agreement within the working group that the new SDP ws-uri attribute that was initially defined within [draft-ietf-bfcpbis-bfcp-websocket] was not BFCP specific and should therefore be defined within a separate draft. There were no competing documents and the draft was immediately adopted as a working group document based on content pulled out of [draft-ietf-bfcpbis-bfcp-websocket]. The draft proceeded without much contention. Reviews were mainly editorial in nature and dealt with the organization of the content and striking the right balance of information between the two drafts such that each stood on its own without unnecessary duplication.  Working group last call resulted on only one substantial review, which clarified when within the SDP offer/answer the new attribute is to be included and how to deal with offerless INVITEs.

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 authors are aware of two server-side implementations and one client-side — none of them is open source. There are also partial client and server implementations that exercise what is covered in this draft. Other companies indicated plans to implement this in their WebRTC gateway.

Personnel:

Who is the Document Shepherd? Who is the Responsible Area Director?
Charles Eckel  is the document shepherd.
Alissa Cooper  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 has been reviewed several times both in its entirety as well as diffs for specific changes. I believe this version of 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?

No.
(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.

This document required expert review from the SDP Directorate. The review as performed by Dan Wing based on draft-ietf-bfcpbis-sdp-ws-uri-05 (see https://mailarchive.ietf.org/arch/msg/bfcpbis/fobMAtc2dmLakNmVxLPJo1um5qk for complete review). The review called attention to some inconsistencies between this draft and draft-ietf-bfcpbis-bfcp-websocket-10, as well as concerns related to ICE interactions and IPv6/IPv4 address preference. These were addressed by draft-ietf-bfcpbis-bfcp-websocket-11 and draft-ietf-bfcpbis-sdp-ws-uri-06.
No other expert reviews were deemed necessary.

(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.

No concerns.

(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?

Yes.

(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 has 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 working group does not have many active participants, but the consensus represents that of the significant portion of those that are active. There are no objections to the current version of the draft.

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.

== Outdated reference: A later version (-11) exists of draft-ietf-bfcpbis-bfcp-websocket-10
== Outdated reference: draft-pd-dispatch-msrp-websocket has been published as RFC 7977
This is deemed acceptable. The first is unavoidable due to there being several work in progress drafts that reference each other. Both can be resolved at the time of publication.

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

This document required expert review from the SDP Directorate. The results of those reviews are listed in (5).

(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?

No.

(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.

No.

(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).

The IANA considerations were thoroughly reviewed and all issues have been resolved.

(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.

Normal IANA review procedures are sufficient.

(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.

None beyond that listed previously.