Hi there,

here a new/updated version of the charter proposal for HyBi wg.
I have tried to include in this version all the suggestions and comments 
received in the mailing list discussion.

please provide comments!

Best Regards
Salvatore Loreto



Proposed Charter for HyBi WG (rev.3)
Last Updated: 2009-10-29
-----------------------------------------------
Chairs:
* TBD
* TBD

Applications Area Director(s):
* Lisa Dusseault <lisa.dusseault@gmail.com>
* Alexey Melnikov <alexey.melnikov@isode.com>
 
Applications Area Advisor:
* Lisa Dusseault <lisa.dusseault@gmail.com>

Mailing Lists:
General Discussion: hybi@ietf.org
To Subscribe: https://www.ietf.org/mailman/listinfo/hybi
Archive: http://www.ietf.org/mail-archive/web/hybi/current/maillist.html

Description of Working Group:
HTTP has in the past been used as a request/response protocol most often,
leading to clients polling for new data or users hitting the refresh button
in their browsers.  Newer web applications are finding ways to push data
from the server to the client as soon as it is available, through a variety
of mechanisms.  The Hypertext-Bidirectional (HyBi) working group will seek
standardization of approaches that HTTP clients, servers, and intermediate
entities can use to communicate with one another in both directions.

Since any modification of the web infrastructure may take a good amount of
time to be deployed, outputs of the working group will include both short
and long term solutions.  The existing web being much more complicated than
it seems, the working group will prioritize the characterization of the
design space, including the web clients, intermediaries, firewalls, NATs,
web servers, etc. into which both solutions will need to be deployed.


For both short and long term work items, a general approach is preferred,
with abstract semantics that can apply to a large number of applications.

The short term approach will be deployable on today's Internet, across
across HTTP proxies, servers and whichever current or historical web
browsers the working group decides upon. Although wide browser support
is a goal, lack of support on any single browser version will not be a
sufficient cause to block consensus.  The short term approach may also
define hints to allow HTTP-updated intermediaries and servers to optimize
traffic.

In the long term, new features will be required of clients, servers, or
intermediaries allowing a more scalable and robust end-to-end experience.

Although multiple protocols exist as starting points for both the short and
long term, backward compatibility with these protocols is not a requirement.
In particular, the working group will liaison with the W3C WebApps 
working group
around the WebSockets protocol and the requirements to support the 
WebSocket API;
if agreed by both parties, the HyBi working group may take on prime 
responsibility
on the specification of the WebSockets protocol.

Wide browser support is a goal for long term solution, however the solution
should also be suitable for clients other than Web Browser.
The Working Group will work to standardize a generic solution that can work
efficiently  in all the environments and elements of the web infrastructure
(e.g. web browser, generic HTTP client, HTTP server and HTTP-aware 
intermediaries
like proxies, load balancers, caches, etc.) and it is not specific for 
just one.


The Working Group should consider:
* Implementer experience
* Impact on existing implementations and deployments
* Ability to achieve broad implementation
* Ability to address broader use cases than may be contemplated by the
original authors

The Working Group will produce one or more documents suitable for
consideration as Proposed Standard that will:
* Define requirements for short- and long-term solutions, including
characterization of the design space
* Define a short-term solution for the bi-directional web, deployable on
today's Internet
* Define a long-term solution for the bi-directional web, which will likely
require modifications to the web infrastructure



Goals and Milestones:
---------------------
Mar-2010:  WGLC on the Design Space characterization (Informational)
May-2010:  WGLC on Requirements document on Short term solution
Jul-2010:  WGLC on Requirements document on Long term solution
Nov-2010:  Requirements to IESG
Mar-2011:  WGLC on Short term solution improvements
Nov-2011:  WGLC on Long term solution protocol