RTP Payload Format for the Enhanced Variable Rate Narrowband-Wideband Codec (EVRC-NW)
draft-ietf-avt-rtp-evrc-nw-10

[Ballot comment]
The -10 version addresses my concern about which version of the 3GPP2 document you're citing.  And IANA has already recorded that they will use this RFC as the registered reference for the audio media types, so my other DISCUSS point is covered.

But (and this is non-blocking) I would still like to see a URL: in Section 17.1, reference [4], can you please add a URL for the 3GPP2 document?  Here's where I found it:
http://www.3gpp2.org/public_html/specs/C.S0014-D_v3.0_EVRC.pdf

If you need xml2rfc code to do this, I can help; send me email.  Or it can be put in as an RFC Editor note, and the RFC Editor will take care of it.

[Ballot discuss]
-- Sections 9.1.1, 9.1.2, and 9.1.3 --

  Published specification:
  The EVRC-NW vocoder is specified in 3GPP2 C.S0014-D.

I can't find the string "EVRC-NW" anywhere in the 3GPP2 document.  Where in that document is the EVRC-NW vocoder specified?

There is no reference to *this* RFC in the registrations for EVRCNW0 and EVRCNW1.  Is that really correct?  If someone's trying to understand what audio/EVRCNW0 is, where, exactly, do they need to look?

[Ballot comment]
Question off the top: Are there no implementations using this now? None were indicated in the shepherd writeup.

Section 5:

  The RTP header marker bit (M) SHALL be set to 1 if the first frame
  carried in the packet contains a speech frame which is the first in a
  talkspurt.  For all other packets the marker bit SHALL be set to zero
  (M=0).

Those SHALLs are meaningless. They should be changed to "will".

Section 6:

  1.  the mode change request field in the interleaved/bundled packet
      format MUST be interpreted according to the definition of the
      RATE_REDUC parameter as defined in EVRC-NW [4].

I don't understand what protocol requirement or interoperability consideration is contained in "MUST be interpreted". Please explain.

  2.  the mode change request field in the interleaved/bundled packet
      format SHOULD be honored by an EVRCNW encoding end point in an
      one-to-one session with a dedicated EVRCNW decoding end point
      such as in a two-party call or in a conference leg.
   
What would it mean to violate the SHOULD? I don't understand what this means.

Section 7:

  Congestion control for RTP SHALL be used in accordance with RFC 3550
  [5], and with any applicable RTP profile, e.g., RFC 3551 [7].

That SHALL doesn't seem useful. Should this simply be, "Congestion control for RTP is discussed in RFC 3550, and in applicable RTP profiles, e.g., RFC 3551. This document does not change those considerations."?

Section 9:

Generally, 2119 language in IANA Considerations is a problem. If it's a protocol requirement, put that in the body of the protocol; don't hide it in IANA Considerations. If it's instructions to IANA, that's not an appropriate use. So, for example:

9.1.1:

  maxinterleave: Maximum number for interleaving length (field LLL in
  the Interleaving Octet)[0..7].  The interleaving lengths used in the
  entire session MUST NOT exceed this maximum value.  If not signaled,
  the maxinterleave length MUST be 5.

You are defining maxinterleave. I presume the limitations on length are explained in [4]. Just make a reference to [4]; don't say MUST/MUST NOT here.

  When this media type is used in the context of transfer over RTP, the
  RTP payload format specified in Section 4.1 of RFC 3558 [6] SHALL be
  used.  In all other contexts, the file format defined in Section 8 of
  RFC XXXX SHALL be used.  See Section 6 of RFC XXXX for details for
  EVRC-NW.
 
Instead:

  This media type can be used with the file format defined in section
  8 of RFC XXXX is used in contexts other than RTP. In context of
  transfers over RTP, the RTP payload format specified in section 4.1
  of RFC 3558 is used for this media type.

If the restriction in usage needs to be called out for interoperability purposes, that belongs elsewhere.

[Ballot comment]


- 6.1: What is the MMM field? Seems to be missing a reference
there.

- section 16: I would encourage you to expand on the reference
to rfc 6562 to say that this codec, like all variable bit rate
codecs, might expose speech even if the flows are strongly
encrypted.

[Ballot comment]

  Please consider the editorial suggestions in the Gen-ART Review
  by Peter Yee on 12-Dec-2012.  The review can be found here:
  http://www.ietf.org/mail-archive/web/gen-art/current/msg07985.html

IANA has reviewed draft-ietf-avt-rtp-evrc-nw-08 and has the following comments:

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

In the Audio Media types registry located at:

http://www.iana.org/assignments/media-types/audio/index.html

three new Audio Media Types will be registered as follows:

EVRCNW [ RFC-to-be ]
EVRCNW0 [ RFC-to-be ]
EVRCNW1 [ RFC-to-be ]

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.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Subject: Last Call:  (RTP payload format for Enhanced Variable Rate Narrowband-Wideband Codec (EVRC-NW)) to Proposed Standard


The IESG has received a request from the Audio/Video Transport Payloads
WG (payload) to consider the following document:
- 'RTP payload format for Enhanced Variable Rate Narrowband-Wideband
  Codec (EVRC-NW)'
  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 2012-12-11. 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


  This document specifies real-time transport protocol (RTP) payload
  formats to be used for the Enhanced Variable Rate Narrowband-Wideband
  Codec (EVRC-NW).  Three media type registrations are included for
  EVRC-NW RTP payload formats.  In addition, a file format is specified
  for transport of EVRC-NW speech data in storage mode applications
  such as e-mail.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-avt-rtp-evrc-nw/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-avt-rtp-evrc-nw/ballot/


The following IPR Declarations may be related to this I-D:

  http://datatracker.ietf.org/ipr/1766/

(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 is a standard track RFC.

It is an RTP payload specification for a 3GPP2 codec.

The title page header indicates it.

(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 specifies real-time transport protocol (RTP) payload formats
to be used for the Enhanced Variable Rate Narrowband-Wideband Codec
(EVRC-NW). Three media type registrations are included for EVRC-NW RTP
payload formats. In addition, a file format is specified for transport of
EVRC-NW speech data in storage mode applications such as e-mail.

Working Group Summary:

This document went through two working group last call. As a result of the
first one there were proposals to add some technical changes that were
consented in the second working group last call.

Document Quality:

This is a payload specification for a 3GPP2 codec and it was reviewed by a
couple of people in the payload working group.

Personnel:

Roni Even is the Document Shepherd and the Responsible Area Director is
Robert Sparks.

(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 reviewed the document very carefully in version -03 during
the WG last call. He has since reviewed the changes with each new version.
A second WG last call was done to verify all changes with the WG before
requesting publication.

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

This document got a good review for an RTP payload specification by people
who had interest in this work.

(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 need for any such review.

(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, the shepherd has confirmed with all authors.

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

There is one IPR disclosure https://datatracker.ietf.org/ipr/1766/ . The
payload mailing list was notified as well as the draft author. There were no
concerns.

(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?

A typical payload specification will be interesting to some of the WG
participants who have interest in using this codec with RTP. As such this
document had a review from individuals who have such interest and
contributed text that was added after the first WGLC.

(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.

No real ID nits in this document.

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

The media subtype registration was reviewed by the shepherd and a request to
review was sent to ietf-type mailing list.
http://www.ietf.org/mail-archive/web/ietf-types/current/msg01598.html. No
comments.

(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 change to other documents already published.

(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 adds a new media subtype EVRC-NW. The document shepherd
verified that the registration template are according to RFC 4855 and
RFC4288 and that they are consistent with the body of the document.

No new IANA registries are defined.



(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.

No new IANA registries.

(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 formal language.

(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 is a standard track RFC.
It is an RTP payload specification for a 3GPP2 codec.
The title page header indicates it.
(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 specifies real-time transport protocol (RTP) payload  formats to be used for the Enhanced Variable Rate Narrowband-Wideband Codec (EVRC-NW).  Three media type registrations are included for EVRC-NW RTP payload formats.  In addition, a file format is specified for transport of EVRC-NW speech data in storage mode applications such as e-mail.

Working Group Summary:
This document went through two working group last call. As a result of the first one there were proposals to add some technical changes that were consented in the second working group last call.
Document Quality:
This is a payload specification for a 3GPP2 codec and it was reviewed by a couple of people in the payload working group.
Personnel:
Roni Even is the Document Shepherd and the Responsible Area Director is Robert Sparks.
(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 reviewed the document very carefully in version -03 during
the WG last call. He has since reviewed the changes with each new version.
A second WG last call was done to verify all changes with the WG before requesting publication.
(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
This document got a good review for an RTP payload specification by people who had interest in this work.
(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 need for any such review.
(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, the shepherd has confirmed with all authors.
(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
There is one IPR disclosure https://datatracker.ietf.org/ipr/1766/ . The payload mailing list was notified as well as the draft author. There were no concerns.
(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?
A typical payload specification will be interesting to some of the WG participants who have interest in using this codec with RTP. As such this document had a review from individuals who have such interest and contributed text that was added after the first WGLC.
(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.
No real ID nits in this document.
(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, media type, and URI type reviews.
The media subtype registration was reviewed by the shepherd and a request to review was sent to ietf-type mailing list.  http://www.ietf.org/mail-archive/web/ietf-types/current/msg01598.html. No comments.
(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 change to other documents already published.
(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 adds a new media subtype EVRC-NW. The document shepherd verified that the registration template are according to RFC 4855 and RFC4288 and that they are consistent with the body of the document.
No new IANA registries are defined.

(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.
No new IANA registries.
(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 formal language.