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Shepherd writeup

PROTO write-up for draft-ietf-radext-radius-fragmentation-08
(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?

This document is aiming for Experimental status. This is the correct choice
because it proposes complex changes to the RADIUS operational model to achieve
transmission of payload sizes beyond the current maximum (4096 bytes). It aims
for backward compatibility when being transmitted over legacy intermediate
proxy systems which are
 not yet upgraded to support the requirements of this document. The real-life
of these changes needs further study; hence Experimental. There are other
approaches to the same problem discussed in the working group, but they are not
backwards compatible to non-upgraded proxies.

(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 Remote Authentication Dial-In User Service (RADIUS) protocol is
   limited to a total packet size of 4096 octets.  Provisions exist for
   fragmenting large amounts of authentication data across multiple
   packets, via Access-Challenge.  No similar provisions exist for
   fragmenting large amounts of authorization data.  This document
   specifies how existing RADIUS mechanisms can be leveraged to provide
   that functionality.  These mechanisms are largely compatible with
   existing implementations, and are designed to be invisible to
   proxies, and "fail-safe" to legacy clients and servers.

Working Group Summary:

   The content of this document was discussed at length in the working
   group, and there are multiple other approaches to the same problem.
   The document thus got significant exposure at the experts of the
   working group. The document has a few rough edges which were the cause
   of discussions. Considering the target status of Experimental, they
   appear minor enough to carry on with the experiment. The authors have
   documented the friction points in their section 11 "Operational
   Considerations". 11.1 in particular shows a process question: is it
   appropriate for an Experimental RFC to update a Standards-track RFC?
   The document attempts to follow that course; if this is ultimately
   agreed after IESG review, the text in that section will be changed

Document Quality:

   At least one implementation is known which implements this
   specification: FreeRADIUS. The sheperd has no information about plans of
   other vendors. There were no particular expert reviews outside the
   working group process; i.e. no MIB doctor review nor Media Type review
   (and no need for those two as the document contains neither MIBs nor
   requests a Media Type). Since the document adds new transport
   capabilities, a thorough review by transport experts (e.g. TSVDIR) during
   IETF Last Call would be appreciated.


   The Document Shepherd is Stefan Winter <>. The
   responsible Area Directors are Benoit Claise <​> and Joel
   Jaeggli <​>.

(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 sheperd was actively reviewing the document during its entire lifecycle,
back then as individual participant in the WG (now chair). For the PROTO
write-up, he gave the then-latest version -06 a fresh read; which resulted in a
number of minor changes which are now the -08 version which is ready for
advancement in the publication process.

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

No concerns; the document was read by and commented on by a comparatively high
 number of participants.

(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.

The document addresses a very specific RADIUS shortcoming and this document's
impact does not appear to matter from a broader perspective at first glance.
However, the document introduces a new transport property for RADIUS
(fragmentation support)
 which deserves a close look by transport area experts. There may be issues with
traversing AAA proxies which are unaware of this document, but those issues have
been uncovered during the WG review process and are enumerated in section 11.

(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.

The issue described in 11.1 had no final conclusive answer; i.e. is it better
to a) have this document update a standards-track document, or b) have an IANA
registry for the flag field assignments, or c) just do nothing. The working
group consensus went for a), which is fine IMO, but the text in 11.1 will need
to be updated with more confident language once it is determined if that course
of action is acceptable process-wise.

From a more general point of view, the entire solution is rather bulky and not
very elegant; but it solves an actual problem and operates despite possible
presence of unaware proxies on the path, which is a significant plus.

(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?

During the PROTO Write-Up, the sheperd asked each author and they all confirmed
that they have no outstanding IPR disclosures.

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

There was no IPR disclosure.

(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 one group of individuals which was pushing for this document: the
ABFAB WG and implementers of the corresponding specs needed this solution and
so far, use cases beyond ABFAB have yet to surface. Naturally, these
participants were most active and drove most of the discussions. However, more
participants than just those were reviewing and commenting on the document, so
there is solid consensus behind the document.

(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
 is publicly available.)

There was one individual who expressed major disconsent during the call for
adoption, and also on various design choices before and after adoption. There
was no threat of appeal though.

(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 thorough.

"The 'Updates: ' line in the draft header should list only the _numbers_
     of the RFCs which will be updated by this document (if approved); it
     should not include the word 'RFC' in the list."

There is a dangling reference [IANA-CONSIDERATIONS] (section pointer) which
can be fixed later in the publication process.

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

There are no MIBs, media types, or URI requests in this document.

(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?

All normative references are issued 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

There are no downward normative references (1 x Informational, 2 x BCP, 3 x

(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.

This document updates RFC6929. That document is mentioned in the introduction,
but not the abstract. The reason why it is omitted in the abstract is because
the relationship
 is relatively minor (a previously reserved flag is defined for use in this
 document) and
because there are two dedicated sections (8 + 11.1) which explain the update
relationship in considerable detail.

(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).

The document introduces two new attributes, one new value for an existing
attribute, and a registry for an enumeration of values for one of those new
attributes. The IANA consideration section contains all the info required by
IANA to perform the reservations in question. Future allocations of the new
registry are defined (RFC required). The name for the registry ('RADIUS
Frag-Status "Code" registry') is reasonable.

(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.

The new registry is 'RFC required'; no experts needed.

(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.

There are no formal language constructs in the document.