Interworking between the Session Initiation Protocol (SIP) and the Extensible Messaging and Presence Protocol (XMPP): Architecture, Addresses, and Error Handling
draft-ietf-stox-core-11

[Ballot comment]

Thanks for handling my discuss point so quickly!

- End of s4: "X2S gw" - on a small screen I nearly jumped
when I thought that said "X25 gw" (I guess I really do need
glasses, sigh:-)

- Labelling the figures might be good.

- Has anyone thought about confusability in the name
mappings? I expected to see a bit of text in the security
considerations but didn't see it.

[Ballot comment]
Oops, I put this in as a DISCUSS because I wanted to DISCUSS it, but it doesn't meet the DISCUSS criteria, so I've cleared.  Sorry for the confusion.  I'd still like you to address this, obviously.

In the architectural diagram on page 5, it appears that the way the protocol flow goes is that romeo's server sends XMPP to juliet's server, and juliet's server responds with SIP.  I don't think this is what you intended—I think that what you intended is that either romeo or juliet could initiate a connection; if romeo initiates, the communication will occur using XMPP, and if juliet initiates, it will occur using SIP.

[Ballot discuss]
In the architectural diagram on page 5, it appears that the way the protocol flow goes is that romeo's server sends XMPP to juliet's server, and juliet's server responds with SIP.  I don't think this is what you intended—I think that what you intended is that either romeo or juliet could initiate a connection; if romeo initiates, the communication will occur using XMPP, and if juliet initiates, it will occur using SIP.

You can clear this DISCUSS either by clarifying the diagram by emphasizing that it works the way I assume it doesn't, if that's the case, or by making it clear that the arrows indicate the direction of initiation, not the direction of communication after initiation, or by convincing me that no clarification is needed, which is perfectly possible.

[Ballot discuss]

(Having now read stox-presence, I'm going to make this
a DISCUSS point in order to make sure we do have
a chat about this point.)

- I wondered why you didn't just say that (D)TLS SHOULD be
used/supported between gateways. Given that all the
relevant bits of code are likely to support that, wouldn't
it be a good thing?

[Ballot comment]

- End of s4: "X2S gw" - on a small screen I nearly jumped
when I thought that said "X25 gw" (I guess I really do need
glasses, sigh:-)

- Labelling the figures might be good.

- Has anyone thought about confusability in the name
mappings? I expected to see a bit of text in the security
considerations but didn't see it.

- It seems a shame to not be able to gateway when the To is
a sips URI at all but I understand that some loss of
security is inevitable for cases like this. Is there any
work planned for an update that would allow gatewaying for
such cases, e.g. if the 1st XMPP server is the one to which
the user is connected and the user is connected using
XMPP/TLS?

[Ballot comment]

- End of s4: "X2S gw" - on a small screen I nearly jumped
when I thought that said "X25 gw" (I guess I really do need
glasses, sigh:-)

- Labelling the figures might be good.

- Has anyone thought about confusability in the name
mappings? I expected to see a bit of text in the security
considerations but didn't see it.

- It seems a shame to not be able to gateway when the To is
a sips URI at all but I understand that some loss of
security is inevitable for cases like this. Is there any
work planned for an update that would allow gatewaying for
such cases, e.g. if the 1st XMPP server is the one to which
the user is connected and the user is connected using
XMPP/TLS?

- I wondered why you didn't just say that (D)TLS SHOULD be
used/supported between gateways. Given that all the
relevant bits of code are likely to support that, wouldn't
it be a good thing?

[Ballot comment]
I assume this is a typo re encrypted/protected:

  Because XMPP lacks a way
  to signal that all hops need to be encrypted,

Https doesn't necessarily imply encryption it depends on the cipher suite chosen.

[Ballot comment]
Section 4 is (nicely) clear on the document architecturally describing a gateway. However, traditionally a gateway is transparent to the entity that communicates with it: When we had SMTP-to-X.400 gateways, the gateway appeared as just another SMTP system that noticed special qualities of the address and then routed the messages appropriately. Section 5 describes something a bit different. It's not clear that what section 5 describes actually is part of the gateway, but rather sounds like a combined server which does failover between the protocols. I don't think this is a showstopper, but it might help implementers significantly if you described in section 5 *where* in the model this function occurs. Right now, it sounds like the server itself does the addressing failover, not the gateway.

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-stox-core version 08, which is currently in Last Call, and has the following comments:

We understand that, upon approval of this document, there are no IANA
Actions that need completion.  IANA requests that the IANA Considerations section of the document remain in place upon publication.

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:  (Interworking between the Session Initiation Protocol (SIP) and the Extensible Messaging and Presence Protocol (XMPP): Architecture, Addresses, and Error Handling) to Proposed Standard


The IESG has received a request from the SIP-TO-XMPP WG (stox) to
consider the following document:
- 'Interworking between the Session Initiation Protocol (SIP) and the
  Extensible Messaging and Presence Protocol (XMPP): Architecture,
  Addresses, and Error Handling'
  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 2013-12-11. 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


  As a foundation for the definition of bidirectional protocol mappings
  between the Session Initiation Protocol (SIP) and the Extensible
  Messaging and Presence Protocol (XMPP), this document specifies the
  architectural assumptions underlying such mappings as well as the
  mapping of addresses and error conditions.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-stox-core/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-stox-core/ballot/


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

PROTO questionnaire for: draft-ietf-stox-core-07

To be Published as: Proposed Standard

Prepared by: Yana Stamcheva (yana@jitsi.org)

(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 requested to be published as Proposed Standard.

(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.

This document specifies the fondation underlying the bidirectional protocol mappings between the Session Initiation Protocol (SIP) and the Extensible Messaging and Presence Protocol (XMPP). Because of the wide deployment of both technologies it is important to clearly define mappings between them for the sake of interworking. This document inaugurates a series of SIP-XMPP interworking specifications by defining the architectural assumptions underlying such mappings as well as the mapping of addresses and error conditions.

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?

This document has been initially reviewed in the DISPATCH WG as per the RAI area process for new work. The STOX WG has been chartered as a result of the submission of this and other documents that aim to define specifications for interworking between the Session Initiation Protocol (SIP) and the Extensible Messaging and Presence Protocol (XMPP) based systems. This document has been subjected to a number of thorough reviews initially in the DISPATCH WG and in the STOX WG after its creation. There were no controversial points regarding it.

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 already several vendors having full or partial implementations of the specification, among which Jabber/Cisco, Kamailio (OpenSER), AG Projects (Silk Server). Some of the people behind these implementations have actively participated in the discussions in the WG.

Personnel

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

Yana Stamcheva is the document shepherd. The responsible area director is Gonzalo Camarillo.

(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 reviewed this version of the document and thinks it is ready for forwarding to IESG for publication.

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

No. The document has been out for a few years and was subjected to thorough reviews. All reviewers' comments have been addressed.

(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.

No.

(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 have no such 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 that references this document 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 WGLC has revealed a solid consensus among the active members of the STOX WG for this document going forward to publishing. There were no objections.

(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.

The document was checked using idnits 2.13.00. There is a warning about the date which is innocuous as well as a warning about an outdated reference to an earlier version of a draft. Both will be addressed by the RFC Editor.

There's also a possible down-reference warning, but it seems a false positive, because it is a reference to UNICODE, which is indeed a normative reference in this case.

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

No formal reviews other than review in the STOX WG are required for this document.

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

Yes, all references in the document exist either in the normative or the informative sections.

(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).

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.

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.

No reviews or automated checks were required as this document does not use any formal language requiring such.