Streams, protocols, documents and fragments

Didier PH Martin martind at
Fri Feb 26 23:49:05 GMT 1999


I thought this would be of interest to the people in the XML Streams,
protocols, documents and fragments thread.

Didier PH Martin
mailto:martind at
---------------- Forwarded  Message ----------------------

Date: Fri, 26 Feb 1999 10:30:26 PST
From: Chris Newman <chris at INNOSOFT.COM>
To: ietf-applcore at

Welcome to the ietf-applcore mailing list.  We now have a tentative BOF
slot in Minneapolis:

APPLCORE has tentatively been scheduled as follows:

	Monday, March 15 at 1300-1500
		other groups scheduled at that time:
			ion, rmonmib, idr, ipsec, megaco, ippm, uswg
I'm working on a detailed agenda for the BOF feel free to post suggested
topics.  Here's the proposed charter I drafted, which will be discussed at
the BOF:

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 clients or servers.

In order to keep the WG in focus, the following items are explicitly

* 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 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
  * 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

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.

---------------- End of Forwarded Message ---------------

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