Pseudo Content Delivery Protocol (CDP) for Protecting Multiple Source Flows in the Forward Error Correction (FEC) Framework
draft-ietf-fecframe-pseudo-cdp-05

[Ballot comment]
Same question as Wes':
"I didn't find a very clear description of why doing this is a good thing,
rather than just keeping separate repair flows.  For instance, is it intended
to have a savings in packet count, does it impact latency, does it minimize
encoder/decoder state to be kept, etc?"

[Ballot comment]

  The authors agreed to make some changes based on the comments provided
  in the Gen-ART Review by Miguel Garcia on 27-Sep-2012, but they have
  not appeared yet.

[Ballot comment]
1) no action required - I have to admit that when I first read this draft I thought it odd that it's called a pseudo CDP, but I now get that this draft is supposed to be like a cookbook for how to put everything together to get a CDP.

2) a: r/full-pledged/full-fledged

3) s1: (let's assume it does ;) r/aims at providing/provides

4) s2: Probably nit picking here a bit, but are you also importing the 2119 language at the end of s2 in RFC 6363?  If not maybe:

  This document uses all the definitions and abbreviations from Section
  2 of [RFC6363] minus the 2119-requirements language.

or something like that.

5) Where's the bit about how the security protocol gets picked!?  I guess I'm just saying an even better non-trivial scenario would have included security.

[Ballot comment]
I have no problem with the publication of this document, but do have some non-blocking comments/questions...

1. I support Wes' comments on this draft.

2. The abstract refers to a "full-pledged" protocol, I assume this should be a "full-fledged" protocol.

3. The last sentence of the abstract seems odd.  Do you really mean for this approach to "design a protocol"?  I would think that it would make more sense to say form/develop/implement a CDP.

4. I am curious if there is a well-accepted definition of what a CDP provides.  How can a reader determine if this approach really provides the necessary functions needed for a CDP?  Are there aspects of CDPs that this approach does not provide?

5. Section 3 states that both the source and destination need to know the Flow ID and that the Flow ID is generated from header fields such as IP addresses and transport-layer port numbers.  Are there implications for this approach introduced by NATs and other types of middleboxes?

6. The Security Considerations section references the Security Considerations in RFC 6363, which is good.  Would any of the security issues in RFC 6364 also apply?

[Ballot comment]
I didn't find a very clear description of why doing this is a good thing, rather than just keeping separate repair flows.  For instance, is it intended to have a savings in packet count, does it impact latency, does it minimize encoder/decoder state to be kept, etc?

It was not clear to me whether the rates of the N source flows come into play or need to be aligned in some way (i.e. if they don't have fixed rates, have odd harmoics, or could have phase issues in how they present bits into the encoder).  For instance, if some flows stall and others don't, does the encoder need to idle fill in order to have enough input to produce the repair blocks? If there are some assumptions on this, it really should be made clear, as it could impact the effectiveness or latency of the FEC.

IANA has reviewed draft-ietf-fecframe-pseudo-cdp-04, which is currently
in Last Call, and has the following comments:

IANA understands that, upon approval of this document, there are no
IANA Actions that need completion.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Subject: Last Call:  (Pseudo Content Delivery Protocol (CDP) for Protecting Multiple Source Flows in FEC Framework) to Informational RFC


The IESG has received a request from the FEC Framework WG (fecframe) to
consider the following document:
- 'Pseudo Content Delivery Protocol (CDP) for Protecting Multiple Source
  Flows in FEC Framework'
  as Informational RFC

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 2012-10-01. 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 provides a pseudo Content Delivery Protocol (CDP) to
  protect multiple source flows with one or more repair flows based on
  the FEC Framework and the Session Description Protocol (SDP) elements
  defined for the framework.  The purpose of the document is not to
  provide a full-pledged protocol, but to show how the defined
  framework and SDP elements can be combined together to design a CDP.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-fecframe-pseudo-cdp/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-fecframe-pseudo-cdp/ballot/


No IPR declarations have been submitted directly on this I-D.

(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?

RFC informational due to wg consensus. The title page indicates
Informational Track.

(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 a pseudo Content Delivery Protocol (CDP) to
protect multiple source flows with one or more repair flows based on
the FEC Framework (RFC6363) and the Session Description Protocol (SDP)
elements defined for the framework. The purpose of the document is
not to provide a full-pledged protocol, but to show how the defined
framework and SDP elements can be combined together to design a CDP.

Working Group Summary

There is consensus within the FECFrame WG to publish this document.
The document has been actively discussed on the wg list and in wg
meetings. There was no controversy with the progression of this
document.

Document Quality

Are there existing implementations of the protocol? Have a significant
number of vendors indicated their plan to implement the specification?
Are there any reviewers that merit special mention as having done a
thorough review, e.g., one that resulted in important changes or a
conclusion that the document had no substantive issues? If there was a
MIB Doctor, Media Type or other expert review, what was its course
(briefly)? In the case of a Media Type review, on what date was the
request posted?

No Implementations.

Who is the Document Shepherd? Who is the Responsible Area Director?

Greg Shepherd is the document shepherd and Martin Stiemerling 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 read the document. The AD read the document. The WG has read the
document. It has been successfully run through idnits. This version of
the document is ready for publication.

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

I have no concerns.

(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.

Yes. There is no 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 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?

There is solid WG consensus behind the document. It has undergone
thorough review within the AVT and FEC communities. The document has
been actively discussed on the WG mailing list and in WG meetings.

(10) Has anyone threatened an appeal or otherwise indicated extreme
discontent? If so, please summarize 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 nits.

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

No required formal review.

(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?

All normative references are to completed work.

(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, publication of this document will not change the status of any
existing RFCs.

(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 considerations are clear and detailed.

(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 expert review necessary.

(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.

Not applicable