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Shepherd writeup

(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?

Standards Track. This status is used by all documents that define RTCP-XR
blocks issued by the XRBLOCK WG. The type is indicated on the title page header.

(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 including two new segment types and associated SDP
parameters that allow the reporting of MOS Metrics for use in a range
of RTP applications.

Working Group Summary

The WG reviewed carefully the document several times and there is
good support behind it.

Document Quality

Two vendors indicated that they have similar functionality in their
code and intentions to implement the standard block when approved.
There was one important change to notice which resulted from the SDP
Expert Review which led to the change of the title of the document from
QoE to MOS Metric reporting, which defines better the scope of the document.


Dan Romascanu 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 reviewed the document and I believe that it is ready for publication.

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


(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.

SDP and PM-DIR expert reviews were performed.

(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.


(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.

All the authors confirmed either by answering explicitly my query on
this subject, or by referring to the boilerplate text in the submitted
I-Ds that state that the documents are submitted in full conformance with
the provisions of BCP 78 and BCP 79.

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

No IPR disclosures where submitted on this I-D.

One of the authors (Alan Clark) mentioned that while they (his company) do
not have IPR directly related to the draft, i.e. to the reporting of a MOS
score in an RTCP XR payload, they do have extensive IPR related to the
calculation of voice, audio and video MOS scores and have declared IPR to
both ITU and ETSI in relation to many of the objective MOS estimation
algorithms listed in the draft. His understanding of IETF IPR policy is
that the request for disclosures relates to IPR required to implement the
RFC and not to the computation of values that may be carried by the protocol.

(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 XRBLOCK is not attended by a large number of people nowadays, there are
about ten active contributors, these were in strong consensus in favor
of the document.

(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.)


(11) Identify any ID nits the Document Shepherd has found in this
document. (See and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be

There is one warning about unused reference [RFC5234] which is because the
mention to 5234 is embedded in the code. Another warning about [ATSC] being
a possible downref can be ignored.

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

SDP and PM-DIR reviews were performed, and the comments of the experts
were addressed.

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


(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?


(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.


(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.


(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).

The IANA Considerations Section includes a request to add a new RTCP XR
Block Type value, a request to add a new RTCP XR SDP Parameter, and a request
to create new registry to be called "RTCP XR MOS Metric block - multimedia
application Calculation Algorithm" as a sub-registry of the "RTP Control
Protocol Extended Reports (RTCP XR) Block Type Registry". These requests
are clear and they include all needed information that will allow to IANA
to perform their actions.

(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.

The review process for the registry is "Specification Required"

(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.