Protocol Independent Multicast - Sparse Mode (PIM-SM) Designated Router (DR) Improvement
draft-ietf-pim-dr-improvement-14

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?
Standards Track. It is indicated. It is a protocol extension, and there is no experiment.

(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 provides an extension to the existing protocol which would improve the stability of the PIM protocol with respect to traffic loss and convergence time when the PIM DR role changes.

Working Group Summary
At least a handful of people other than the authors have expressed support, and several people providing reviews. No one is against publishing the document.
There was some discussion how this document relates to another PIM DR document that we are considering adopting. We concluded by adding text to this document, explaining what is different between the documents.

Document Quality
Greg Mirsky, Jake Holland and the shepherd carefully reviewed the document and provided a number of comments. There were no major changes to the protocol though.
One vendor has implemented the protocol extension in this document, and it has been deployed.

Personnel
Shepherd is Stig Venaas. AD is Alvaro Retana.

(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 believes the document is ready. Some changes were made after shepherd's review.

(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.

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.

All authors have confirmed that they are not aware any other IPR than what has been filed.
See the thread https://mailarchive.ietf.org/arch/browse/pim/?gbt=1&index=s9g9EkeS0dA8lGtbZVitMLzGOfU

(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
disclosures.
IPR was filed after adoption, but before we did last call. The WG was aware of the IPR as it was posted to the list, but I don't recall any discussion now. I believe we want to publish this regardless of the 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? 
A handful of people apart from the authors are supporting it, which is pretty good for this WG. None against 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.)
No

(11) Identify any ID nits the Document Shepherd has found in this
document. (See https://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough.
Very minor. There is an idnits warning about an IPv6 address that is not a documentation address, but this is the address ::, and it needs to be that way.

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.
No formal review needed

(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


(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 8126).
The considerations are clear. I would suggest removing "Option" from the option names though.

(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.

(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

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?
Standards Track. It is indicated. It is a protocol extension, and there is no experiment.

(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 provides an extension to the existing protocol which would improve the stability of the PIM protocol with respect to traffic loss and convergence time when the PIM DR role changes.

Working Group Summary
At least a handful of people other than the authors have expressed support, and several people providing reviews. No one is against publishing the document.
There was some discussion how this document relates to another PIM DR document that we are considering adopting. We concluded by adding text to this document, explaining what is different between the documents.

Document Quality
Greg Mirsky, Jake Holland and the shepherd carefully reviewed the document and provided a number of comments. There were no major changes to the protocol though.
It is not known whether there are implementations. At least one vendor and one operator are interested.
As mentioned below, there are some nits and IANA considerations could be improved. This can be fixed together with AD review comments. Should have been fixed before requesting publication.

Personnel
Shepherd is Stig Venaas. AD is Alvaro Retana.

(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 believes the document is ready. Some changes were made after shepherd's review.

(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.

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.

All authors have confirmed that they are not aware any other IPR than what has been filed.
See the thread https://mailarchive.ietf.org/arch/browse/pim/?gbt=1&index=s9g9EkeS0dA8lGtbZVitMLzGOfU

(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
disclosures.
IPR was filed after adoption, but before we did last call. The WG was aware of the IPR as it was posted to the list, but I don't recall any discussion now. I believe we want to publish this regardless of the 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? 
A handful of people apart from the authors are supporting it, which is pretty good for this WG. None against 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.)
No

(11) Identify any ID nits the Document Shepherd has found in this
document. (See https://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough.
Very minor. One unused reference should have been removed. Reference in abstract should have been removed. There is a warning about an IPv6 address that is not a documentation address, but this is the address ::, and it needs to be that way.

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.
No formal review needed

(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


(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 8126).

It is pretty obvious what is needed, but I think the IANA considerations should have specified the names of the new hello options, so that IANA doesn't need to look through the rest of the document to try to figure it out. Section 3.1 is titled "DR Address Option format" and the option name is "DR Address". Likewise section 3.2 is titled "BDR Address Option format".
It could also be stated clearly that it is for the "PIM Hello Options" registry.
Maybe this can be fixed before proceed with publication, along with other comments from AD review?

(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.

(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

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?
Standards Track. It is indicated. It is a protocol extension, and there is no experiment.

(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 provides an extension to the existing protocol which would improve the stability of the PIM protocol with respect to traffic loss and convergence time when the PIM DR role changes.

Working Group Summary
At least a handful of people other than the authors have expressed support, and several people providing reviews. No one is against publishing the document.
There was some discussion how this document relates to another PIM DR document that we are considering adopting. We concluded by adding text to this document, explaining what is different between the documents.

Document Quality
Greg Mirsky, Jake Holland and the shepherd carefully reviewed the document and provided a number of comments. There were no major changes to the protocol though.
It is not known whether there are implementations. At least one vendor and one operator are interested.
As mentioned below, there are some nits and IANA considerations could be improved. This can be fixed together with AD review comments. Should have been fixed before requesting publication.

Personnel
Shepherd is Stig Venaas. AD is Alvaro Retana.

(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 believes the document is ready. Some changes were made after shepherd's review.

(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.

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.

All authors have confirmed that they are not aware any other IPR than what has been filed.
See the thread https://mailarchive.ietf.org/arch/browse/pim/?gbt=1&index=s9g9EkeS0dA8lGtbZVitMLzGOfU

(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
disclosures.
IPR was filed after adoption, but before we did last call. The WG was aware of the IPR as it was posted to the list, but I don't recall any discussion now. I believe we want to publish this regardless of the 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? 
A handful of people apart from the authors are supporting it, which is pretty good for this WG. None against 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.)
No

(11) Identify any ID nits the Document Shepherd has found in this
document. (See https://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough.
Very minor. One unused reference should have been removed. Reference in abstract should have been removed. There is a warning about an IPv6 address that is not a documentation address, but this is the address ::, and it needs to be that way.

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.
No formal review needed

(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


(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 8126).

It is pretty obvious what is needed, but I think the IANA considerations should have specified the names of the new hello options, so that IANA doesn't need to look through the rest of the document to try to figure it out. Section 3.1 is titled "DR Address Option format" and the option name is "DR Address". Likewise section 3.2 is titled "BDR Address Option format".
It could also be stated clearly that it is for the "PIM Hello Options" registry.
Maybe this can be fixed before proceed with publication, along with other comments from AD review?

(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.

(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