RTP Control Protocol (RTCP) Extended Report (XR) for Post-Repair Loss Count Metrics
draft-ietf-xrblock-rtcp-xr-post-repair-loss-count-11

[Ballot discuss]
The following MUST versus RECOMMENDED is still an issue

  post-repair loss count: 16 bits

      Total number of packets finally lost after applying one or more
      loss-repair methods, e.g., FEC and/or retransmission, during the
      actual sequence number range indicated by begin_seq and end_seq.
      This metric MUST NOT count the lost packets for which repair might
      still be possible.

This goes against

2. Interval report

  Some implementations may align the begin_seq and end_seq number with
  the highest sequence numbers of consecutive RTCP RRs (RTCP interval).
  This is NOT RECOMMENDED as packets that are not yet repaired in this
  current RTCP interval and may repaired in the future will not be
  reported in subsequent reports.


I understand the explanations you provided in the past. The only logical solution is to change the "MUST NOT" with "NOT RECOMMENDED"

[Ballot comment]


Thanks, the draft improved.
However, There are still sentences that I had to read multiple times, to "get" them. I believe that I have spent enough time on this draft by now. So will not comment on those.

-

  in 6 still to be repaired lost packet = cumulative number of packets
  lost - cumulative post-repair loss count -  cumulative repaired loss
  count

"in 6"?

- Why doesn't this section 3 mention "repaired loss count"?

[Ballot discuss]
1. post-repair loss count: 16 bits

      Total number of packets finally lost after applying one or more
      loss-repair methods, e.g., FEC and/or retransmission, during the
      actual sequence number range indicated by begin_seq and end_seq.
      This metric MUST NOT count the lost packets for which repair might
      still be possible. Note that this metric MUST measure only primary
      source RTP packets.

I see the MUST above, and the RECOMMENDED below.

  Thus it is RECOMMENDED that this report block should be generated
  only for those source packets that have no further chance of being
  repaired and not for any other packets. This block needs to specify
  its own measurement period to avoid ambiguity in calculating the
  post-repair loss count.

I was expecting a MUST instead of RECOMMENDED.
Did the WG discuss that point?
In which situation would you need this exception, and what could you actually deduce if you apply it?


2. Question:
  The relationship
  between the metrics in this report block and the pre-repair loss
  metric of RTCP XR could be expressed in the following formula:

      cumulative number of packets lost = post-repair loss count +
      repaired loss count + to be repaired lost packet

  "cumulative number of packets lost" is the metric from RTCP SR/RR.
  "post-repair loss count" and "repaired loss count" are the metrics
  defined in this draft.

Am I correct that it's difficult (if not impossible) to compare those values with a small granularity because:
1. RFC 3550 section 6.4.1 SR: Sender Report RTCP Packet sends the "cumulative number of packets lost" with timestamps
2. draft-ietf-xrblock-rtcp-xr-post-repair-loss-count sends "post-repair loss count" and "repaired loss count" with sequence numbers.
On top of that, the intervals are different!

[Ballot comment]
- The abstract mentions:
  This document defines an RTP Control Protocol (RTCP) Extended Report
  (XR) Block that allows reporting of post-repair loss count metrics
  for a range of RTP applications.

This draft introduces two metrics: post-repair loss count and repaired loss count
This is slightly confusing.
I believe you want to include the two metrics in the abstract.
Alternatively:
NEW:
  This document defines an RTP Control Protocol (RTCP) Extended Report
  (XR) Block that allows reporting of post-repair loss-related metrics
  for a range of RTP applications.


-
  In
  addition,  another metric, repaired loss count, is also introduced in
  this report block for calculating the pre-repair loss count during
  the this range,

the this -> chose one.

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-xrblock-rtcp-xr-post-repair-loss-count-07.  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 block type will be registered as follows:

BT: [ TBD-at-registration ]
Name: Post-Repair Loss Count Metrics Report Block
Reference: [ RFC-to-be ]

IANA Note: As this document requests registrations in a Specification Required (see RFC 5226) registry, we will initiate the required Expert Review via a separate request. Expert review will need to be completed before your document can be approved for publication as an RFC.

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 is to be registered as follows:

Parameter: post-repair-loss-count
Reference: [ RFC-to-be ]

IANA Note: As this document requests registrations in a Specification Required (see RFC 5226) registry, we will initiate the required Expert Review via a separate request. Expert review will need to be completed before your document can be approved for publication as an RFC.

IANA understands that, upon approval of this document, these two actions are the only ones required to be completed.

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. 

Please note that IANA cannot reserve specific values. However, early allocation is available for some types of registrations. For more information, please see RFC 7120.

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 Post-Repair Loss Count Metrics) 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 Post-Repair Loss
  Count Metrics'
  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 2014-12-26. 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 defines an RTP Control Protocol (RTCP) Extended Report
  (XR) Block that allows reporting of post-repair loss count metrics
  for a range of RTP applications.





The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-xrblock-rtcp-xr-post-repair-loss-count/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-xrblock-rtcp-xr-post-repair-loss-count/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

(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 defines an RTP Control Protocol (RTCP) Extended Report
  (XR) Block that allows reporting of post-repair loss count metrics
  for a range of RTP applications.


Working Group Summary

  The WG reached a good consensus on approving this document.

Document Quality

  A number of experts in the WG as well as the SDP reviewer in the MMUSIC
  WG reviewed the document.

Personnel

  Dan Romascanu 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.

  The document is ready.

(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 need for special review excepting the usual reviews that belong to the
  process.

(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 consensus is solid. The number of active participants in the WG
  is small, but all are dedicated and knowleadgeable experts.

(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 problem. 

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

  SDP review was performed and the recommendations were taken into
  consideration.

(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?

  N/A

(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.

  N/A

(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).

  IANA is required to allocate a new RTCP XR Block Type value and a new
  RTCP XR SDP Parameter. Both request are OK, and contatinformation
  is provided.
 
(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 registries are created by this document.

(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.

  N/A