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Shepherd writeup

Updated 5/3/2014 to reflect current Document status. Edit performed by
Shepherding AD Joel Jaeggli.

(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

  The advantages and benefits provided by multicast technologies are
  well known.  There are a number of application areas that are ideal
  candidates for the use of multicast, including media broadcasting,
  video conferencing, collaboration, real-time data feeds, data
  replication, and software updates.  Unfortunately, many of these
  applications lack multicast connectivity to networks that carry
  traffic generated by multicast sources.  The reasons for the lack of
  connectivity vary, but are primarily the result of service provider
  policies and network limitations.

  Automatic Multicast Tunneling (AMT) is a protocol that uses UDP-based
  encapsulation to overcome the aforementioned lack of multicast
  connectivity.  AMT enables sites, hosts or applications that do not
  have native multicast access to a network with multicast connectivity
  to a source, to request and receive SSM [RFC4607] and ASM [RFC1112]
  traffic from a network that does provide multicast connectivity to
  that source.

Working Group Summary

  This document has received strong support from the working group and no
  major controversies existed prior to the arriving at the IESG with
  this document.

  Subsequent to the previous IESG review, efforts have been made to address IESG
  discuss issues, deal with IANA concerns and spin up new work associated with
  congestion guidance for multicast applications.

Document Quality

  A number of AMT implementations exist today and significant deployment
  experience has been documented.  This document has received thorough
  review from the working group, and many have contributed to this effort
  over the last 11+ years.  In particular, Dave Thaler, Tom Pusateri,
  Thomas Morin and Greg Bumgardner deserve credit for most of the
  authorship of this document, and Bob Sayko, Doug Nortz and their
  colleagues at ATT deserve credit for extremely thorough review of the


  Lenny Giuliano is the Document Shepherd, Ron Bonica is the
  Responsible Area Director.


  IANA Considerations

  IPv4 and IPv6 Anycast Prefix Allocation

  IANA should allocate an IPv4 prefix and an IPv6 prefix dedicated to
  the public AMT Relays to advertise to the native multicast backbone
  (as described in Section 4.1.4).  The prefix length should be
  determined by the IANA; the prefix should be large enough to
  guarantee advertisement in the default-free BGP networks.


  A prefix length of 24 will meet this requirement.


  A prefix length of 32 will meet this requirement.  IANA has
  previously set aside the range 2001::/16 for allocating prefixes for
  this purpose.

  IPv4 Address Prefix Allocation for IGMP Source Addresses

  IANA should allocate an IPv4 prefix dedicated for use in IGMP
  messages exchanged between gateways and relays.  This address range
  is intended for use within tunnels constructed between a gateway and
  relay, and as such, is not intended to be globally routable.

  A prefix length of 24 will meet this requirement.

  UDP Port number

  IANA has reserved UDP port number 2268 for AMT.

(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.

Document was reviewed by the Shepherd, who feels it is ready for

Document has been reviewed in detail by IANA.  Previous IESG review can be seen
as part of the document history

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

No, the document has undergone thorough review from a number of folks
in the WG.

During previous IETF last call and IESG review an number of issues were
addressed. With  respect to the content of the draft it has been very
thoroughly reviewed.

(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.

Not that I am aware of.

(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.  Doc has been thoroughly reviewed and all issues seem to be

Guidelines for multicast applications with respect to congestion awareness or
avoidance is work that has begun in order to address concerns expressed in
transport are review and by the previous and present transport ADs. This is
important work, however amt relay routers as with other forms of multicast
tunnel routers are not ultimately in a position to alter the transmission rate
of the multicast source, applications running on multicast recievers may be in
a position to alter their behavior in response to exigent conditions (see
section and

(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.


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

Not aware of any, nor any recollection of any WG discussion regarding IPR.

(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 appears to 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.)

Not that I am aware of.

(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

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

Not aware of any.

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

Yes, there are both normative and informative references.

(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?

Not that I am aware of.  All normative references point to RFCs.

(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.

There are no normative references to any informational RFCs.

(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).

IANA has signed off on draft 17

(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.

See IANA considerations above.

(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.