As required by RFC 4858, this is the current template for the Document
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 document discusses generic issues when combining an AQM mechanism with a Scheduling mechanism in combination. This is intended to help implementers conceptualize the interactions, but does not account as a formal protocol. The intended status is properly reflected in the title page.
(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:
This note discusses implementation strategies for coupled queuing and mark/drop algorithms. In the discussion of Active Queue Management, there has been discussion of the coupling of queue management (scheduling) algorithms with mark/drop (aqm) algorithms. This note is Informational, intended to describe reasonable possibilities without constraining outcomes. This is not so much about "right" or "wrong" as it is "what might be reasonable", and discusses several possible implementation strategies. Also, while queuing might be implemented in almost any layer, specifically the document addresses queues that might be used in the Differentiated Services Architecture, and are therefore at or below the IP layer.
Working Group Summary
Was there anything in WG process that is worth noting? For
example, was there controversy about particular points or
were there decisions where the consensus was particularly
This document emerged to capture some of the discussions within the WG around the combination of scheduling and AQM mechanisms, and to clarify the discussion, as well as providing some guidance as to how to implement such a combination.
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?
The WG is actively looking at specific combined algorithms (e.g. FQ-Codel), which have been widely recognized as being more effective than either algorithm alone. There exists deployed code, as well as simulation code for this particular combination, but many other combinations, as described in the document, of different scheduling and queue management algorithms are possible.
Document Shepherd - Wesley Eddy
Responsible Area Director - Martin Stiemerling
(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 document is mostly descriptive; some minor nits regarding language (simplification and disambiguation for non-native speakers) have been raised. Thorough technical review was performed, while the content captures the spirit of discussions within the group as to the merit of combining the different classes of algorithms.
(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
The document leans heavy on the Differentiated Services Architecture language. There is good overlap of the TSVWG responsible for that and the AQM group. Reviews by RTG - in particular additional implementers - is suggested.
(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
(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.
To the best of the shepherds knowledge, yes.
(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding 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?
The entire WG has participated in the discussion, and the document has widespread consensus. No concerns were raised that have not been addressed.
(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 http://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
There are no normative downrefs. There are informational references to other WG documents that are not yet last called. If the RFC Editor prefers, the document may be kept by the RFC Editor before publishing until these documents are ready, but we do not have any requirement for this.
(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 necessary.
(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.
No status change of 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).
No IANA 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.
(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.
No formal sections within document.