Session Traversal Utilities for NAT (STUN) Message Handling for SIP Back-to-Back User Agents (B2BUAs)
draft-ietf-straw-b2bua-stun-08

[Ballot comment]

- 4.2, but maybe also elsewhere: should such a b2bua be
REQUIRED to announce itself as a b2bua that forces itself
into the media stream in some manner? Or more broadly, if we
are now (for the 1st time?) standardising b2bua behaviours,
then ought we mandate that such entities make their
prescence or even some flavour of their functionality known
in-band?  Even if we do not mandate such behaviour,
shouldn't we at least define how a b2bua that wants to be
visible ought do that? (And if we have done the above
already, or discussed and discarded the above already, then
great, and that shows how much I know:-)

[Ballot comment]

- 4.2, but maybe also elsewhere: should such a b2bua be
REQUIRED to announce itself as a b2bua that forces itself
into the media stream in some manner? Or more broadly, if we
are now (for the 1st time?) standardising b2bua behaviours,
then ought we mandate that such entities make their
prescence or even some flavour of their functionality known
in-band?  Even if we do not mandate such behaviour,
shouldn't we at least define how a b2bua that wants to be
visible ought do that? (And if we have done the above
already, or discussed and discarded the above alrady, then
great, and that shows how much I know:-)

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

IANA has reviewed draft-ietf-straw-b2bua-stun-05, 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.

While it is helpful for the IANA Considerations section of the document to remain in place upon publication, if the authors prefer to remove it, IANA doesn't object.

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

[Ballot comment]
No objection, but a couple of places where the text seemed rough:

In this text:

  For these
  and other reasons, B2BUAs were already being used by SIP domains for
  other SIP and media-related purposes began to use proprietary
  mechanisms to enable SIP devices behind NATs to communicate across
  the NAT.
 
Does this sentence parse?

In this text:

  The most commonly used approach to solve these issues is
  "restricted-latching", whereby the B2BUA will not latch to any
  packets from a source public IP address other than the one the SIP UA
  uses for SIP signaling.
 
Is the phrase "will not latch to" clear to the intended reader? The sentence is defining a type of latching, but there's not a description of what latching means in the general sense. The following section says terms are defined in https://tools.ietf.org/html/rfc7092, but I didn't see "latch" in a quick text search over there. Is the reference to https://tools.ietf.org/html/rfc7362 earlier in the paragraph also to the description of "latching"?

In this text:

  o  A B2BUA that acts as a simple media relay effectively unaware of
      anything that is transported and only modifies the transport
      header (could be UDP/IP) of the media packets.

  o  A B2BUA that performs a media-aware role.  It inspects and
      potentially modifies RTP or RTP Control Protocol (RTCP) headers;
      but it does not modify the payload of RTP/RTCP.

  o  A B2BUA that performs a media-termination role and operates at the
      media payload layer, such as RTP/RTCP payload (e.g., a
      transcoder).

  When such a B2BUA operating on a media plane is involved in a session
  between two endpoints performing ICE, then it MUST follow the
  behavior described in Section 4.
 
I"m reading "such a B2BUA" as a reference to the third bullet, but it would be clearer to me if both places used the same terms ("operates at the media payload layer" vs. "operating on a media plane").

[Ballot comment]
I just finished reading this draft and agree with the SecDir review assessment that this draft does not add additional security considerations.  The SecDir reviewer had some good points on the abstract and introduction that I do think would be helpful to improve the readability of the draft and would like you to consider these updates.

https://www.ietf.org/mail-archive/web/secdir/current/msg05687.html

[Ballot comment]
-- Section 1 --

  For these
  and other reasons, B2BUAs were already being used by SIP domains for
  other SIP and media-related purposes began to use proprietary
  mechanisms to enable SIP devices behind NATs to communicate across
  the NAT.

I can't parse that sentence.  The "began" doesn't seem to be the right part of speech, or maybr the second "for" is wrong.  Something, anyway.

Update: the author has provided good replacement text:
NEW:
For these reasons, B2BUAs were being used by SIP domains for
SIP and media-related purposes. These B2BUAs use proprietary
mechanisms to enable SIP devices behind NATs to communicate across
the NAT.
END

[Ballot discuss]
This is a DISCUSS purely because I want to discuss it; whatever the result is, I will be clearing the DISCUSS, and not delaying the document on this point:  The end of Section 1 (and other places) seems to say that this document updates 7092 by giving new mandatory behaviour for certain types of B2BUAs.  Am I misunderstanding that, or should this document formally "update" 7092?

[Ballot comment]
-- Section 1 --

  For these
  and other reasons, B2BUAs were already being used by SIP domains for
  other SIP and media-related purposes began to use proprietary
  mechanisms to enable SIP devices behind NATs to communicate across
  the NAT.

I can't parse that sentence.  The "began" doesn't seem to be the right part of speech, or maybr the second "for" is wrong.  Something, anyway.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Revised Last Call:  (Session Traversal Utilities for NAT (STUN) Message Handling for Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs)) to Proposed Standard


The IESG has received a request from the Sip Traversal Required for
Applications to Work WG (straw) to consider the following document:
- 'Session Traversal Utilities for NAT (STUN) Message Handling for
  Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs)'
  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 2015-05-13. 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.

This document contains a normative reference to an Informational RFC: RFC 7092

Abstract


  Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs)
  are often designed to be on the media path, rather than just
  intercepting signaling.  This means that B2BUAs often act on the
  media path leading to separate media legs that the B2BUA correlates
  and bridges together.  When acting on the media path, B2BUAs are
  likely to receive Session Traversal Utilities for NAT (STUN) packets
  as part of Interactive Connectivity Establishment (ICE) processing.

  This document defines behavior for a B2BUA performing ICE processing.
  The goal of this draft is to ensure that B2BUAs properly handle STUN
  messages received as part of the ICE procedures used for NAT and
  Firewall traversal of multimedia sessions.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-straw-b2bua-stun/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-straw-b2bua-stun/ballot/


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

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Session Traversal Utilities for NAT (STUN) Message Handling for Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs)) to Proposed Standard


The IESG has received a request from the Sip Traversal Required for
Applications to Work WG (straw) to consider the following document:
- 'Session Traversal Utilities for NAT (STUN) Message Handling for
  Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs)'
  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 2015-05-13. 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


  Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs)
  are often designed to be on the media path, rather than just
  intercepting signaling.  This means that B2BUAs often act on the
  media path leading to separate media legs that the B2BUA correlates
  and bridges together.  When acting on the media path, B2BUAs are
  likely to receive Session Traversal Utilities for NAT (STUN) packets
  as part of Interactive Connectivity Establishment (ICE) processing.

  This document defines behavior for a B2BUA performing ICE processing.
  The goal of this draft is to ensure that B2BUAs properly handle STUN
  messages received as part of the ICE procedures used for NAT and
  Firewall traversal of multimedia sessions.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-straw-b2bua-stun/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-straw-b2bua-stun/ballot/


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

Notification list changed to draft-ietf-straw-b2bua-stun.ad@ietf.org, draft-ietf-straw-b2bua-stun.shepherd@ietf.org, draft-ietf-straw-b2bua-stun@ietf.org, straw-chairs@ietf.org, straw@ietf.org, "Victor Pascual" <victor.pascual.avila@gmail.com> from draft-ietf-straw-b2bua-stun.ad@ietf.org, draft-ietf-straw-b2bua-stun.shepherd@ietf.org, draft-ietf-straw-b2bua-stun@ietf.org, straw-chairs@ietf.org, straw@ietf.org

(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)?

Intended status: Standards Track


Why is this the proper type of RFC?


The document contains normative procedures.


Is this type of RFC indicated in the title page header? Yes

(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.

Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs) are
often designed to be on the media path, rather than just intercepting
signaling.  This means that B2BUAs often act on the media path leading
to separate media legs that the B2BUA correlates and bridges together. 
When acting on the media path, B2BUAs are likely to receive Session
Traversal Utilities for NAT (STUN) packets as part of Interactive
Connectivity Establishment (ICE) processing. It is critical that B2BUAs
handle these STUN messages properly.

This document defines behavior for a B2BUA performing ICE processing.
The goal of this document is to ensure that ICE used for NAT and
Firewall traversal of multimedia sessions works when there are B2BUAs in
place and the B2BUAs handle STUN messages properly.

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 WG path of this document was reasonably short and efficient. Several
technical comments were made during reviews and all were resolved with
consensus.
There is consensus in the STRAW WG to publish this document.

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 guidelines and procedures in the document is based on input  and
experience from the implementer community.

Personnel:
Who is the Document Shepherd?


Victor Pascual (victor.pascual.avila@gmail.com -- STRAW WG co-chair) Who
is the Responsible Area Director?
Richard Barnes



(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 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.

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.

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

(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 as a whole understand and agree with 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


(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.

idnits 2.13.01


/tmp/draft-ietf-straw-b2bua-stun-04.txt:


Checking boilerplate required by RFC 5378 and the IETF Trust (see http://trustee.ietf.org/license-info):
------------------------------------------------------------------------
---- No issues found here.
Checking nits according to http://www.ietf.org/id-info/1id-
guidelines.txt:
------------------------------------------------------------------------
---- No issues found here.
Checking nits according to http://www.ietf.org/id-info/checklist  :
------------------------------------------------------------------------
---- No issues found here.
Miscellaneous warnings:
------------------------------------------------------------------------
----


No issues found here.


Checking references for intended status: Proposed Standard
------------------------------------------------------------------------
----


(See RFCs 3967 and 4897 for information about using normative references
to lower-maturity documents in RFCs)

No issues found here. No nits found.

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

Not Applicable


(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).

This document makes no request or reference to 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 request to 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.

This document does not use formal language such as XML code, BNF rules
or MIB definitions.

Note added '(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)?

Intended status: Standards Track


Why is this the proper type of RFC?


The document contains normative procedures.


Is this type of RFC indicated in the title page header? Yes

(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.

Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs) are
often designed to be on the media path, rather than just intercepting
signaling.  This means that B2BUAs often act on the media path leading
to separate media legs that the B2BUA correlates and bridges together. 
When acting on the media path, B2BUAs are likely to receive Session
Traversal Utilities for NAT (STUN) packets as part of Interactive
Connectivity Establishment (ICE) processing. It is critical that B2BUAs
handle these STUN messages properly.

This document defines behavior for a B2BUA performing ICE processing.
The goal of this document is to ensure that ICE used for NAT and
Firewall traversal of multimedia sessions works when there are B2BUAs in
place and the B2BUAs handle STUN messages properly.

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 WG path of this document was reasonably short and efficient. Several
technical comments were made during reviews and all were resolved with
consensus.
There is consensus in the STRAW WG to publish this document.

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 guidelines and procedures in the document is based on input  and
experience from the implementer community.

Personnel:
Who is the Document Shepherd?


Victor Pascual (victor.pascual.avila@gmail.com -- STRAW WG co-chair) Who
is the Responsible Area Director?
Richard Barnes



(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 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.

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.

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

(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 as a whole understand and agree with 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


(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.

idnits 2.13.01


/tmp/draft-ietf-straw-b2bua-stun-04.txt:


Checking boilerplate required by RFC 5378 and the IETF Trust (see http://trustee.ietf.org/license-info):
------------------------------------------------------------------------
---- No issues found here.
Checking nits according to http://www.ietf.org/id-info/1id-
guidelines.txt:
------------------------------------------------------------------------
---- No issues found here.
Checking nits according to http://www.ietf.org/id-info/checklist  :
------------------------------------------------------------------------
---- No issues found here.
Miscellaneous warnings:
------------------------------------------------------------------------
----


No issues found here.


Checking references for intended status: Proposed Standard
------------------------------------------------------------------------
----


(See RFCs 3967 and 4897 for information about using normative references
to lower-maturity documents in RFCs)

No issues found here. No nits found.

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

Not Applicable


(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).

This document makes no request or reference to 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 request to 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.

This document does not use formal language such as XML code, BNF rules
or MIB definitions.'