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Requirements for the extension of the IGMP/MLD proxy functionality to support multiple upstream interfaces
draft-ietf-pim-multiple-upstreams-reqs-08

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Document history

Date Rev. By Action
2019-05-13
08 (System) Document has expired
2019-05-13
08 (System) IESG state changed to Dead from AD is watching
2018-11-09
08 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-08.txt
2018-11-09
08 (System) New version approved
2018-11-09
08 (System) Request for posting confirmation emailed to previous authors: Luis Contreras , Nicolai Leymann , Hitoshi Asaeda , Carlos Bernardos
2018-11-09
08 Luis Contreras Uploaded new revision
2018-11-06
07 Alvaro Retana
As discussed in today's pim meeting at IETF 103, I am returning this document to the WG.

Potential future steps include (but are not limited …
As discussed in today's pim meeting at IETF 103, I am returning this document to the WG.

Potential future steps include (but are not limited to): (1) incorporate the requirements into a solution document, and, (2) use this document as a reference for the WG to develop a solution.  It was decided in the WG meeting that this document won't be published in the IETF stream.
2018-11-06
07 Alvaro Retana IESG state changed to AD is watching from AD Evaluation::AD Followup
2018-11-04
07 Stig Venaas Added to session: IETF-103: pim  Tue-1350
2018-10-22
07 (System) Sub state has been changed to AD Followup from Revised ID Needed
2018-10-22
07 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-07.txt
2018-10-22
07 (System) New version approved
2018-10-22
07 (System) Request for posting confirmation emailed to previous authors: Luis Contreras , Nicolai Leymann , Hitoshi Asaeda , Carlos Bernardos
2018-10-22
07 Luis Contreras Uploaded new revision
2018-01-31
06 Alvaro Retana
=== AD Review of draft-ietf-pim-multiple-upstreams-reqs-06 ===
https://mailarchive.ietf.org/arch/msg/pim/DUe-SfbHlt2jf8hSsrcmpowNMKo/?qid=ab8b90c7de389c24ceb76f9efd0348bf

Dear authors:

I just finished reading this document.

In general, I am not a big fan of requirement …
=== AD Review of draft-ietf-pim-multiple-upstreams-reqs-06 ===
https://mailarchive.ietf.org/arch/msg/pim/DUe-SfbHlt2jf8hSsrcmpowNMKo/?qid=ab8b90c7de389c24ceb76f9efd0348bf

Dear authors:

I just finished reading this document.

In general, I am not a big fan of requirement documents on their own -- if
the problem is important enough then ideally there will be solution work
done as well.  I seem to remember some talk about potential solutions (as
far back as IETF 92), but didn't find a clearly related draft (or one that
references this document) in pim, mboned or even magma.  I want to
encourage the WG to take on work that addresses the scenarios described in
this document.

The document presents some applicable scenarios, which at times are
constraint by assuming that "both providers offer distinct multicast
groups" or that "only one of the upstream interfaces is active in receiving
the multicast content" -- leaving the decision to be straight forward: use
the upstream that provides the required group/source/service.  I then found
the resulting requirements relatively weak and general.  For one, it seems
as if the bulk of the requirements can be summarized as:

- the proxy should deliver control messages from/to the user to/from the
corresponding upstream

- the proxy should be able to select an upstream based on the requested
service (group/source combination, when applicable) or other criteria (e.g.
load balancing)

Those two requirements seem both generic and pretty obvious to me...and
don't offer too many details; for example: Should the user be able to set
the other criteria?  Is some criteria specific to the proxy itself and it's
operator (load balancing, for example)?  The description (related to load
balancing) talks about "split the demand, alleviating the bandwidth
requirements", but the requirements mention "balance...as a function of the
group", or "consider the source", both of which have no direct relationship
to helping with the bw requirements.

When the document does get into slightly more interesting scenarios, the
resulting requirements are not as specific as I would have expected to
later successfully build a solution that addresses them:

- "should be able of rapidly switching from the active to the standby
upstream interface in case of network failure, transparently to the end
user"  How fast is that?  Is there something more specific that could be
used to quantify?  Does it depend on the application?  Are there
expectations on the network failure detection?

- "decide...according to the situation of the user with respect to the
service migration"...or..."according to the situation of the group and
source included in the request with respect to the service migration."
Besides knowing which upstream provides the service, is there something
else related to the "situation"?

At times the document reads like a marketing brochure...  For example: "For
the multicast service, the use of an IGMP/MLD proxy with multiple upstream
interfaces in those switches can provide service flexibility in a
lightweight and simpler manner if compared with PIM-routing based
alternatives."  flexible, lightweight, simple...  Nice!  But the
requirements don't directly seem to address those qualifications or offer a
way for an eventual solution to measure flexibility, simplicity,
lightweightness (?).

Another example: "it is now possible to implement channel-based or
subscriber-based upstream selection".  Based on the requirements, I take
that to mean that we can select an upstream based on what the subscriber
wants (source/group).  However, I could also interpret "subscriber-based"
as related to the subscriber him/herself -- is the intent that the proxy
could take into account personally identifiable information (who I am or
where I am, for example) when deciding not just which upstream to use but
whether to even provide the service?  Maybe I'm reading too much into
that, but clarifying that there are no requirements related to exchanging
or using information that would explicitly identify the subscriber
him/herself would help.

I have other comments below.

Let me be clear.  We're at this point of the process because the WG thinks
there's value in publishing this document — I’m not pushing back.  The
objective of my comments are aimed at making this document the best it can
be -- again, so we can build solutions based on the requirements.  I think
that in its current state, this document doesn’t provide valuable direction
for those eventual solutions.

I would like to see a revision to the document, or at least a response to
my comments before starting the IETF Last Call.

Thanks!

Alvaro.




C1. The examples and scenarios are described based on 2 upstreams.  I'm
assuming that the requirements don't really change if it was more than 2,
right?  It would be nice if that statement was made at some point: "all
this is applicable to 2 or more upstreams".

C2. 4.1.1.1.: "Since the use case assumes that each provider offers
distinct multicast groups, the IGMP/MLD proxy should be able to identify
inconsistencies in the SSM requests when a source S does not deliver a
certain group G."  What does it mean to "identify inconsistencies"?  What
are "inconsistencies"?

C3. PIM and PIM solutions are mentioned several times, but there's no
reference.  Please add some.

C4. Same comment for "existing IGMP/MLD proxy functionality".

C5. In 4.1.2.1, what's the difference between the first and last
requirement?

  o  The IGMP/MLD proxy should be able to deliver multicast control
    messages sent by the end user to the corresponding active upstream
    interface.
  ...
  o  The IGMP/MLD proxy should be able to deliver IGMP/MLD messages
    sent by the end user (for both ASM and SSM modes) to the
    corresponding active upstream interface.

C6. The case in 4.1.3 (Load balancing for multicast traffic in the metro
segment) seems to contradict the assumptions in the previous sections:
"both providers offer distinct multicast groups", "only one of the upstream
interfaces is active in receiving the multicast content".  I realize that
the scenarios are different, or that the requirements describe different
areas of (not necessarily concurrent) functionality -- it would be nice to
be specific about that.

C7. Security Considerations: "Apart from that, if proper mechanisms (i.e.,
implementation practices) are in place for channel-based or
subscriber-based upstream interface selection, Denial of Service attacks
can be prevented."  Proper mechanisms like what?  Please provide references.
2018-01-31
06 Alvaro Retana IESG state changed to AD Evaluation::Revised I-D Needed from AD Evaluation
2018-01-30
06 Alvaro Retana This document now replaces draft-contreras-pim-multiple-upstreams-reqs instead of None
2018-01-29
06 Alvaro Retana IESG state changed to AD Evaluation from Publication Requested
2018-01-29
06 Alvaro Retana Notification list changed to Stig Venaas <stig@venaas.com>, aretana.ietf@gmail.com from Stig Venaas <stig@venaas.com>
2017-11-20
06 Stig Venaas
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 …
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?

Informational. This should be appropriate for a requirements document.
The type is indicated.

(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 purpose of the document is to define the requirements for a MLD (for IPv6) or IGMP (for IPv4) proxy with multiple interfaces covering a variety of applicability scenarios.

Working Group Summary
The people that have been showing the most interest in solutions have been involved in writing this requirements document. At least a handful of other people have indicated support, and no one has indicated any issues with the document.

Document Quality
The document is informational and discusses requirements. There are no known issues. Some minor issues were raised in working group last call, and they have all been addressed.

Personnel
Document Shepherd Stig Venaas
Responsible AD 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 reviewed the document as part of working group last call. The issues found have been 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 additional review needed.

(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, all authors confirmed that they are not aware of any IPR.

(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? 

Fairly solid. The authors are active working group participants. A handful of other people have supported the document, and no one in the working group has any issues.

(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.

No nits.

(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 5226).

No considerations.

(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, no formal language.
2017-11-20
06 Stig Venaas Responsible AD changed to Alvaro Retana
2017-11-20
06 Stig Venaas IETF WG state changed to Submitted to IESG for Publication from WG Document
2017-11-20
06 Stig Venaas IESG state changed to Publication Requested
2017-11-20
06 Stig Venaas IESG process started in state Publication Requested
2017-11-20
06 Stig Venaas Changed document writeup
2017-11-20
06 Stig Venaas Notification list changed to Stig Venaas <stig@venaas.com>
2017-11-20
06 Stig Venaas Document shepherd changed to Stig Venaas
2017-11-20
06 Stig Venaas Intended Status changed to Informational from None
2017-11-16
06 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-06.txt
2017-11-16
06 (System) New version approved
2017-11-16
06 (System) Request for posting confirmation emailed to previous authors: Luis Contreras , Nicolai Leymann , Hitoshi Asaeda , Carlos Bernardos
2017-11-16
06 Luis Contreras Uploaded new revision
2017-10-30
05 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-05.txt
2017-10-30
05 (System) New version approved
2017-10-30
05 (System) Request for posting confirmation emailed to previous authors: Luis Contreras , Nicolai Leymann , Hitoshi Asaeda , Carlos Bernardos
2017-10-30
05 Luis Contreras Uploaded new revision
2017-07-02
04 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-04.txt
2017-07-02
04 (System) New version approved
2017-07-02
04 (System) Request for posting confirmation emailed to previous authors: Luis Contreras , Nicolai Leymann , Hitoshi Asaeda , Carlos Bernardos
2017-07-02
04 Luis Contreras Uploaded new revision
2017-01-09
03 (System) Document has expired
2016-07-08
03 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-03.txt
2016-07-07
02 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-02.txt
2015-10-19
01 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-01.txt
2015-07-08
00 Luis Contreras New version available: draft-ietf-pim-multiple-upstreams-reqs-00.txt