FW (from Bryan): ISSUE-227 (When is new technology "new technology"?): How Useful will the CT Guidelines Doc be, without extensions to HTTP? [Content Transformation Guidelines]

Copying to ct list

-----Original Message-----
From: member-bpwg-request@w3.org [mailto:member-bpwg-request@w3.org] On
Behalf Of Sullivan, Bryan
Sent: 20 November 2007 19:03
To: Mobile Web Best Practices Working Group WG
Subject: RE: ISSUE-227 (When is new technology "new technology"?): How
Useful will the CT Guidelines Doc be, without extensions to HTTP?
[Content Transformation Guidelines]


Jo,
This is a good representation of the problem at hand and the key
options. Like I said in Boston, any choice will damn us, including
inaction. Especially functional changes (being new or semantically
different/reused) to headers or values causes a variety of issues, e.g.
to interoperability (e.g. cache control as one of the more problematic
areas of variance in browser behavior). But progress demands crossing
that boundary when we have to. The question is can the CTTF make any
substantial progress on CT without such functional changes?

The core requirements that I offered in
http://lists.w3.org/Archives/Public/public-bpwg-ct/2007Nov/0000.html
point to the need of several things that cannot be provided, imo,
without functional changes, e.g.
- awareness of CT support in delivery context entities
- entity selection of CT "features" to enable/disable
- semantic disclosure of alternative representations (RFC 2295 may help,
but from an implementation perspective would still be largely new)

Other than these functional changes, all we can do is describe what the
CT proxy should offer/do based upon current headers or other out-of-band
information (e.g. from administration or at the presentation layer,
without specifying how it was determined). That would be valuable at
least though to identify where the real functional gaps are, and focus
the followup work (which may require a charter change).

Best regards,
Bryan Sullivan | AT&T | Service Standards
bryan.sullivan@att.com
-----Original Message-----
From: member-bpwg-request@w3.org [mailto:member-bpwg-request@w3.org] On
Behalf Of Mobile Web Best Practices Working Group Issue Tracker
Sent: Tuesday, November 20, 2007 9:42 AM
To: member-bpwg@w3.org
Subject: ISSUE-227 (When is new technology "new technology"?): How
Useful will the CT Guidelines Doc be, without extensions to HTTP?
[Content Transformation Guidelines]



ISSUE-227 (When is new technology "new technology"?): How Useful will
the CT Guidelines Doc be, without extensions to HTTP? [Content
Transformation Guidelines]

http://www.w3.org/2005/MWI/BPWG/Group/track/issues/

Raised by: Jo Rabin
On product: Content Transformation Guidelines

I took an action (ACTION-602) at today's CT Task Force Meeting to raise
this as a formal issue.

The options seem to me to be:

a) Cut back the proposed text to discussion of how to use no-transform
and the Vary header, together with various heuristics relating to the
nature of content (e.g. XHTML-MP, link headers and the like)
b) Introduce new values for Cache-Control, which appears to be condoned
by HTTP/1.1 in the section on Cache-Control
c) Try to use some headers that are introduced in RFC 2295 and have been
registered
d) Invent entirely new headers

If we stuck to just a) we would achieve very little beyond what has
already been promulgated, e.g. by dotMobi. On the other hand, going
beyond that could be considered only borderline within our charter
remit. Especially option d) which I don't favour.

Jo

Received on Wednesday, 21 November 2007 09:01:53 UTC