RTP Control Protocol (RTCP) Extended Report (XR) Block for the Bytes Discarded Metric
RFC 7243

[Ballot comment]
Thanks for a well-written document.

As pointed out by Vijay in his Gen-ART review, in Section 6,

  In some situations, returning very
  detailed error information (e.g., over-range measurement or
  measurement unavailable) using this report block can provide an
  attacker with insight into the security processing.  Implementers
  should consider the guidance in [I-D.ietf-avt-srtp-not-mandatory] for
  using appropriate security mechanisms, i.e., where security is a
  concern, the implementation should apply encryption and
  authentication to the report block.

the text does not really describe what security issue is being an issue here. I also read draft-ietf-avt-srtp-not-mandatory, but it did not talk about this specific issue. In the e-mail discussion a brief mention of the rational was given. I think it would be useful to add some text here. But this is an editorial issue, not a blocking-level comment.

[Ballot comment]
I put myself in the shoes of the operator looking at the different extended reports, and I'm trying to understand how to correlate the number of discarded bytes with  number of discarded packets from the different extended reports.

From the document, there could be 3 different extended reports reporting the number of discarded packets:

  o  Reporting the number of discarded packets in a measurement
      interval, i.e., during either the last reporting interval or since
      the beginning of the session, as indicated by a flag in the
      suggested XR report [RFC7002].  If an endpoint needs to report
      packet discard due to other reasons than early- and late-arrival
      (for example, discard due to duplication, redundancy, etc.)  then
      it should consider using the Discarded Packets Report Block
      [RFC7002].

  o  Reporting gaps and bursts of discarded packets during a
      measurement interval, i.e., the last reporting interval or the
      duration of the session [RFC7003].

  o  Reporting run-length encoding of discarded packet during a
      measurement interval, i.e., between a set of sequence numbers
      [I-D.ietf-xrblock-rtcp-xr-discard-rle-metrics].


First of all, it would be nice to mention that the measurement intervals from the different extended reports are synchronized.
Talking to Dan Romacanu (btw thanks Dan), I understand that the number of bytes can be correlated to the number of packet in bullet 1 (RFC 7002) and/or in the bullet 3 ([I-D.ietf-xrblock-rtcp-xr-discard-rle-metrics]), depending on the flag value expressing whether we speak about delta or running counters.
A few sentences (or a new section) about this would be an extremely useful addition from an operational point of view.

Note: it was confusing to me that  [I-D.ietf-xrblock-rtcp-xr-discard-rle-metrics] refers to http://tools.ietf.org/html/draft-ietf-xrblock-rtcp-xr-discard-rle-metrics-06, a very old version of the draft ... which still contains the bytes extended report. Mentioning RFC 7097 obviously solves that one. Thanks again Dan for gently highlighting the obvious to me :-)

[Ballot comment]
-- Section 7.3 --

In the discussion of draft-ietf-xrblock-rtcp-xr-synchronization, Pete brought up the question of using an individual as the contact point for working group stuff.  I suggest that this document should use the same resolution as that one, specifying the RAI ADs .

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric-01.  Authors should review the comments and/or questions below.  Please report any inaccuracies and respond to any questions as soon as possible.

We received the following comments/questions from the IANA's reviewer:

IANA understands that, upon approval of this document, there are two actions which IANA must complete.

First, in the RTCP XR Block Type subregistry of the RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry located at:

http://www.iana.org/assignments/rtcp-xr-block-types/

a new XR Block Type will be registered as follows:

BT: [ TBD-at-registration ]
Name: BDR (Bytes Discarded Report)
Reference: [ RFC-to-be ]

Second, in the RTCP XR SDP Parameters registry in the RTP Control Protocol Extended Reports (RTCP XR) Session Description Protocol (SDP) Parameters Registry located at:

http://www.iana.org/assignments/rtcp-xr-sdp-parameters/

a new XR SDP Parameter will be registered as follows:

Parameter: discard-bytes
Reference: [ RFC-to-be ]

IANA understands that these are the only actions 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.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (RTP Control Protocol (RTCP) Extended Report (XR) for Bytes Discarded Metric) to Proposed Standard


The IESG has received a request from the Metric Blocks for use with
RTCP's Extended Report Framework WG (xrblock) to consider the following
document:
- 'RTP Control Protocol (RTCP) Extended Report (XR) for Bytes Discarded
  Metric'
  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 2014-02-04. 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 RTP Control Protocol (RTCP) is used in conjunction with the Real-
  time Transport Protocol (RTP) in to provide a variety of short-term
  and long-term reception statistics.  The available reporting may
  include aggregate information across longer periods of time as well
  as individual packet reporting.  This document specifies a report
  computing the bytes discarded from the de-jitter buffer after
  successful reception.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric/ballot/


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

I'd like to request that draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric-01,
"RTP Control Protocol (RTCP) Extended Report (XR) for Bytes Discarded
Metric", be published as a Standard Track RFC.

I have reviewed the draft in detail and XRBLOCK working
group was given plenty of opportunity to comment through
several WGLCs.

The contents of this document previously belonged to
draft-ietf-xrblock-xr-discard-rle-metrics [RFC7097]. Towards the end
of the IESG review, a point was made that during PM-DIR review,
Alan Clark raised a point that the two metrics that were originally covered
in RFC7097 should indeed be in a separate document. So that
implementers are not bound to implement two different metrics to
claim compliance to the RFC.

After a discussion at the IETF87, the WG decided to take out the text
regarding discarded-metric for the benefit of implementers into a
separate draft which is the draft mentioned in this publication request.

The contents of this document hasn't been changed in any technical
form since it was separated from RFC7097, this was confirmed by
few WG members during the WGLC and by me.

** Proto-Writeup *******************

Document shepherd write-up for draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric-01.txt

(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?

The document is being requested as a Standards Track RFC.

The document defines one new Extended Report (XR)
Report Block [RFC 3611] and standards track is appropriate for this document.

Standards Track is indicated in 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 draft defines a new block type to augment those defined in
[RFC3611] for use in a range of RTP applications. The new block type
supports the report computing the bytes discarded from the
de-jitter buffer after successful reception.

Working Group Summary

There were several points of debate within the working group; however,
none were particularly rough and authors and commentators came up
with the text that resolves any issues thus consensus was achieved in
all cases.


Document Quality

This document has been reviewed by numerous people within
XRBLOCK through three rounds of WGLCs (Including
two that took place when it was part of RFC7097) the document
resolved any outstanding issues.

The document has been reviewed by SDP directorate post WGLC
for SDP extensions defined, any issues raised were resolved.

The document has been reviewed by PM-DIR and the existence
of this document addresses the issue raised (separating this document
from RFC7097).

Personnel

Shida Schubert is the Document Shepherd.
Gonzalo Camarillo 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.

I have reviewed the last two iterations of this document in previous form
(part of RFC7097) and two iterations in its current form, including providing
technical and editorial review comments during the WGLC reviews.
All of my comments and that of others provided during WGLC are addressed.

(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.

There are 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?

Yes, there is strong consensus.

(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 concern..

(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 are required for this document.

(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 (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).

Appropriate reservations have been included for IANA registries.

(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.

None required.