minutes, HTTP Working Group, IETF June 96, Montreal

Minutes for the HTTP Working Group, 36th IETF, reported by Ted Hardie
and Larry Masinter.

The minutes reflect the topics, discussion, and decisions made at the
working group meetings over the two days.

Related activities:

WTS had submitted its drafts on S-HTTP for last call and was not
meeting at this IETF. An INDEX-BOF met Monday. It began with a report
of the W3C sponsored workshop on web indexing. This work is of
interest to HTTP development, but does not currently look like it will
result in a working group forming.  A URN BOF will meet Thursday.
This is important to HTTP-WG members since the use of URNs might also
have an impact on caching models within HTTP.  There is some work
starting on versioning on the web. There will be a workshop in July on
the topic, held at NaviSoft (San Mateo, CA).

Content negotiation:

There are three current drafts that deal with negotiation some form
and content negotiation in particular (transparent negotiation, UA
headers, and PEP).

draft-holtman-http-negotiation-01.txt:

The group is interested in the work Koen Holtman has done, but worried
about the timetable for filling in some of the important pieces--a
volunteer was requested to help Koen with completing his model and
draft.  No volunteer was available at the meeting, but interest
remains if someone can commit to working on it.

draft-mutz-http-attributes-00.txt:

Andrew Mutz described the draft on UA headers. The reception was
mixed.  Some members of the group felt that it provided a good,
standard method for providing information about UA capabilities which
might not otherwise be available (particularly in the context of PDAs,
braille terminals, or voice output).  Others felt that this was the
thin edge of a wedge for a host of UA headers which did not belong in
a transport layer protocol.

A discussion of the use of a generic UA header revealed problems with
caching and limitations on how Vary headers could respond. The use of
MIME envelopes to accomplish the same effect was also proposed.

draft-khare-http-pep-01.txt:

Henrik Nielsen reviewed the status of PEP. In his talk, he pointed out
how PEP could be used for the UA negotiation of the Mutz draft as an
example.  He believes that the continuing use of RFC822 headers, while
easy, is not effective as it cannot handle order dependency nor the
difference between need and want.  He noted that many of the previous
problems with PEP (lack of a class hierarchy or q factors, etc) are
being addressed now within the W3C during test implementations.  A new
draft will be available with those changes by August 1, 1996.  It is
important to describe how PEP will interact with caching, especially
with older caches; worries that this sort of mechanism will radically
increase the number of cachable variants are a work item.

General discussion:

Harald Alvestrand pointed out that the group does not have a unified
model; we have a desire to create a language to describe what the user
wants and a language to describe what the server has and we don't have
a unified model for bringing those together; until that model comes
together--neither is going forward.

As far as UA attributes, the question is not really whether or not to
support web servers generating variable content--variability is
already being done based on User-Agent and other factors, but we need
a model for handling it long term.

Keith Moore then pointed at that we need to be careful about how far
down this path we go; some of what we want is outside of the box of
HTTP, and that we don't want to set things up so that we have to use
HTTP for everything or bootstrap everything through HTTP.  Look for a
coherent method of handling the near and middle-term problems.

We will continue to work on all three drafts; a final decision will be
deferred until there are revised drafts and some implementation
experience is available.  

draft-hallam-http-logfile-00.txt, draft-hallam-http-session-id-00.txt,
draft-hallam-http-proxy-note-00.txt:

We discussed the three drafts originally submitted by Philip
Hallam-Baker.  The group agreed that demographics were important,
because people sometimes deliberately defeated caching in order to get
good demographics, but that many demographic methods actual fell
outside the scope of the working group because they do not require
anything be done to the protocol.  Jeff Mogul and Paul Leach agreed to
put forward a draft by the end of July which would describe a simple
method for doing a very baseline user/hit count with an extension to
the cache-control directive.  It was also suggested that a
requirements document for demographics would be useful, as many had
different ideas of what was needed.  Among them were:

  user counts, hit counts, click trails, session identifiers, client
  capability counts

John Klensin and Keith Moore then reminded the group that many
business models do not allow for the automatic sharing of data, and
that the notion that anyone can cache information should not be a
basic part of our model.  If we do work on demographics and
interactions between servers and caches, we should do so with the
understanding that this work is limited to situations where a trust
relationship exists between the server and cache.

draft-ietf-http-digest-aa-04.txt (Digest Authentication):

This will go to last call immediately. Most (but not all) of the
implementors in the room agreed that they would implement it.

draft-ietf-http-state-mgmt-02.txt (State Management):

This will need some editorial changes before being sent for last call,
and Dave Kristol will be producing a new draft.  This draft will
remove the word Proposed from the title, and clarify certain other
potential areas of concern. This work will happen within 3-4 weeks.
Marc Soloman is working on some other issues with Dave on this.

Implementation Guide:

Martin Hamilton <martin@mrrl.lut.ac.uk> agreed to gather items which
might be better described in an implementation guide; he will create a
web page of this, and post the URL.  It is possible that we will
produce an Informational RFC based on this material, possibly being
able to move some of the implementation advice out of the HTTP/1.1
spec when it is next revised. The group also agreed that the creation
of this document would not mean removing all explanatory material from
the HTTP/1.1 spec.

HTTP/1.1 issues:

The group agreed that the current handling of comment text for
matching on Vary fields was conservative (since only LWS might be
ignored), but decided that it would be easier to begin with this model
and loosen it later, if necessary.

The issue of how to handle character sets was raised, in that the
current draft's handling does not match the IAB workshop's general
recommendation on character sets (though the workshop did include a
"grandfather" clause for existing protocols).  After a great deal of
discussion, it was agreed that a small group (Larry, Paul Leach,
Francois) to generate new wording which requires a charset label on
all text types, and which explicitly uses the "unknown" charset when it
is not known.

[[note: this issue has been reexamined subsequently on the mailing
list.]]

At the close of the discussion of 1.1, Jim Gettys was hailed with
thunderous applause for his work on getting 1.1 ready.

HTTP-NG report:

Work on HTTP-NG is ongoing, including work on a multiplexing protocol.
Jim Gettys made an appeal for data with which to determine what
problems need to be solved for HTTP-ng.  Without data we are likely to
work on the wrong problems. It was suggested that if someone wants
data, the right process is to write an RFC suggesting what kind of
data should be gathered and where it should be sent. Jim will write a
short document describing what data is needed and giving a limited
time period in which it will be accepted.

HTTP/1.2 issues:

There are only a few issues that people want to see resolved in HTTP
for which we do not currently have Internet-Drafts.  Paul Leach has
agreed to write a draft on sticky headers, compressed headers, and
context identifiers.

Michael Ottati asked whether there was interest in the group in
creating a standard method for handling atomic transactions (a commit
facility).  Those interested should contact him at
Ottati_Michael@tandem.com; he will also write up a draft describe the
basic facilities he's interested in, for comments by the group.

Revised Charter

The group needs to revise the charter. We identified the following
milestones:


July 2: (Gettys) Revised HTTP/1.1 draft with
		    charset labelling
		    ;q= tag changes

July 30: (Mogul, Leach): draft on 'hit count' additions

Aug 1:   (Nielsen) revised PEP draft
Aug 1:   (Mutz)    revised User Agent attributes draft
Aug 1:   (Leach)   draft on sticky headers, short names for headers, and
 	  	   context identifiers

undated:  revised content negotiation draft
undated:  HTTP Implementation Guidelines draft

Dec 96: all remaining documents to Last Call

Target is to close working group by next IETF with work completed.  We
may not need meeting at the December IETF. Subsequent work (e.g., on
HTTP-NG) may happen by creating a new working group with a new mailing
list, etc.

Received on Tuesday, 2 July 1996 23:51:34 UTC