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Re: Application "core protocol" BOF/WG idea

From: Chris Newman <Chris.Newman@innosoft.com>
Date: Thu, 28 Jan 1999 17:02:57 -0800 (PST)
To: discuss@apps.ietf.org
Message-id: <Pine.SOL.3.95.990128160253.24010Q-100000@elwood.innosoft.com>
Rough concensus appears to be heading in the direction of liking part or
all of this proposal (including three voluteers for WG chair or document
editor positions) and I have yet to hear a compelling negative response. 
But rough concensus is not yet sufficiently clear, so please continue to
express your opinions.  Here are responses to the general concerns
expressed so far: 

> The task is too big and should be constrained to the
> problem-identification and history document.

If it's useful identifying the problem, then it's also useful to propose a
solution.  Futhermore, if you constrain the working group to the point
that it doesn't have a product which is sufficiently compelling to
motivate participants to work, then the effort will die.  While the
history/problem-statement document would be interesting and useful, I
doubt it is sufficient by itself to motivate active participation.

My motivation stems from my realization that the IETF usually can't say
"no"; it can only say "use this instead", "take your proposal elsewhere"
or "fix this problem in your proposal".  There are people who wish to
layer unrelated new protocol services on top of a 167 page HTTP protocol
because they think it gives security and MIME labelling "for free."  I
can't argue with an honest desire to simplify the task of specifying new
protocols, so I want to see a significantly simpler "use this instead"
candidate.  The engineer in me is willing to expend a lot of energy so
that future IETF protocols are simpler and cleaner.  Remove the "core
protocol" task and you remove my motivation and probably that of several
others.

> Isn't this what HTTP-NG is doing?

No.  HTTP-NG has a much larger scope than this proposal.  On the high-end,
the HTTP-NG name implies it's a replacement for a high-level hypertext
transfer application, and is thus out-of-scope for this proposal.  On the
low-end, HTTP-NG met as an IETF "transport area" WG, which indicates a
focus at a much lower level than this proposal permits.  This proposal is
very narrow so it only addresses those problems we (in the applications
area) have solved before and have operational experience with.

> Isn't this a research project?

No.  The proposed charter explicitly rules out-of-scope anything that
hasn't already been done in a deployed IETF protocol.  The fact that
people think this might be a research project or as broad as the HTTP-NG
work suggests the proposed charter needs to be tightened up further, so I
have clarified the initial paragraph to reflect.

> Let's do this in a strict sequence of steps

I have revised the proposed charter so the "core protocol" proposal can't
go to IETF last call until the "history/problem statement" document has
been completed.  However, I think it's a bad idea to attempt to do a
problem statement and requirements without doing a prototype solution in
parallel -- otherwise the problem statement and requirements may not be 
grounded in reality.


I have also added a couple other constraints to the proposed charter to
address other concerns which were expressed. 

		- Chris

------APPLCORE proposed charter V2

The APPLCORE BOF will discuss the following proposed charter:

Application core protocol WG  (APPLCORE)

The IETF has traditionally developed application protocols directly on
top of a raw TCP stream.  However, there is a growing set of problems
which many application protocols have to solve regardless of what the
protocols do.  This WG will identify the common problems that deployed
IETF protocols have solved, identify the successes and failures that
deployed IETF protocols made when addressing these problems and design
a simple core protocol to address these problems.  This core protocol
may then be used by future application protocols to simplify both the
process of protocol design and the complexity of implementing
multi-protocol servers.

In order to keep the WG in focus, the following items are explicitly
out-of-scope:

* Backwards compatibility with existing application protocols
  Backwards compatibility often compromises correct design.  If this
  WG is successful it will impact a great number of future protocols,
  and thus the design errors which backwards compatibility might
  dictate must be avoided.

* Transport layers other than TCP/IP
  This has been a rathole in too many other WGs.

* Protocol models outside the traditional IETF client-server TCP
  application protocol model.
  The IETF doesn't have sufficient past experience in these areas.

* New features
  If a problem hasn't been solved in at least two deployed IETF
  application protocols, then it is out-of-scope for the base core
  protocol spec.  This does not preclude individuals or other groups
  from doing extensions to the core protocol which might be used by
  multiple future application protocols; it just limits the scope of
  the core spec.

* Normative references to other application protocols or non-public specs
  The core protocol has to stand by itself.  It may reference protocol
  building blocks that have been used by several other application
  protocols such as ABNF, language tags, UTF-8, domain names, URLs,
  MIME, SASL, GSSAPI and TLS.  It must avoid normative references to
  full application protocols such as ACAP, HTTP, IMAP, LDAP, and SMTP.
  It must avoid normative references to any document which is not
  freely and publicly available on the Internet.

The WG will produce the following output:

* An Informational RFC documenting the problems identified to solve,
  and giving examples of existing deployed IETF protocols which
  succeeded or made mistakes when solving those problems.  A starting
  list of problems for the WG to discuss (the WG may choose not to
  address some of these) follows:

  * connection user authentication and privacy (e.g., SASL and STARTTLS)
  * server capability/extension announcement (e.g., SMTP EHLO)
  * extensible command/response syntax and structure
  * error status tokens and human readable error text issues
  * syntax for transfer of large (multi-line) objects (e.g., dot-stuffing,
    length counting, chunking)
  * multiple commands in progress at the same time (command ids or tags)
  * unsolicited server messages
  * command pipelining (sending multiple commands without waiting for
    responses)
  * Structured data representation (e.g., RFC 822-style AV pairs, IMAP
    s-expressions, LDAP ASN.1, XDR, etc) in command/response syntax.
  * low bandwidth support (e.g., compression layer or packed binary
    protocol encoding)
  * connection shutdown (QUIT/LOGOUT command)

* A simplicity litmus test to determine if a proposal is acceptably
  simple.  The initial litmus test will be: core protocol spec is less
  than 25 pages.

* A standards track core application protocol specification which uses
  the lessons learned from the informational document and fits the
  litmus test above.  An open source implementation of the complete
  core protocol must exist prior to IETF last call.  The problem
  identification draft (above) must be completed prior to IETF last
  call.

The WG may solicit strawmen for the core application protocol from
multiple document editors and select the one which is technically
best and fits this charter.

The WG may choose to do additional standards track documents which
extend the core protocol as long as they are not new features by the
above definition.

The WG may choose to do one or more APIs for using the core protocol
and adding commands/extensions to it.  These might be informational
or standards track as deemed appropriate.
Received on Thursday, 28 January 1999 20:04:56 GMT

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