- From: Scott Lawrence <lawrence@agranat.com>
- Date: Mon, 31 Aug 1998 22:25:39 +0000
- To: HTTP-NG Comments <www-http-ng-comments@w3.org>
- CC: iesg@ietf.org
The HTTP-NG BOF in Chicago was very helpfull to me both in
understanding what has been done in the W3C Activity and in
clarifying my thinking about how it should proceed within the IETF.
My view of the essential elements of what HTTP-NG has done so far is
that they have described:
1) A framework that more precisely specifies application message
semantics (the object-oriented NG interfaces).
2) A more compact binary encoding for Web application messages.
3) An application message boundary mechanism (the webmux fragments).
4) An application association mechanism that supports multiple
interleaved associations over a single transport layer connection
(webmux sessions), including:
4a) the association setup uses a very simple endpoint definition
is be easily inspected by firewalls.
5) A mechanism for describing a service stack below the application
to provide additional services (compression, security).
Despite the fact that many other proposed protocols have been
choosing HTTP as a 'transport', I was suprised to hear that the
HTTP-NG effort was being considered within the Transport Area rather
than Application. The main arguments that I heard in Chicago in
favor of this were: that other protocols were doing it anyway (people
are making a poor choice for the wrong reasons, so we should make a
poor choice that will validate it?); and that webmux credits would
have dangerous potential interactions with TCP flow control that
needed transport expertise to understand (very good reason!).
Having spent some time thinking about the list above, I have come to
believe that some of the reasons why so many recent applications
have been choosing HTTP as a substrate (it isn't a transport no
matter how many times you call it one) is that it provides (3), (4),
(4a), and (5) from that list. These things are important
requirements of a very large subset of all application layer
protocols, and TCP does not provide them.
I don't believe that a case can be made for putting work on (1) or
(2) into the Transport Area, and I'm not even convinced that an
object-oriented (or other) interface definition framework is a good
direction for HTTP to go. A binary encoding for HTTP/1.1 would be
easy to do without the new paradigm, and would be a very interesting
experiment.
I do believe that 3 through 5 are desperately needed, and while my
computer science professors would all have called those Session
Layer, I'm willing to call them Transport if it means we can get
them done once and well so that other applications can use them.
With that in mind, I humbly offer my suggestion for a Working Group
name: Enhanced Application Transport Services (eats).
--
Scott Lawrence Consulting Engineer <lawrence@agranat.com>
Agranat Systems, Inc. Embedded Web Technology http://www.agranat.com/
Received on Monday, 31 August 1998 18:25:18 UTC