Re: Fwd:HTTP server driven content negotiation

From: Johan Hjelm (
Date: Mon, Mar 08 1999

Message-Id: <4.1.19990308150627.00c026d0@>
Date: Mon, 08 Mar 1999 15:11:18 +0100
To: Philipp Hoschka <>,
From: Johan Hjelm <>
Subject: Re: Fwd:HTTP server driven content negotiation

Actually, this problem is exactly the same as when you have a pager or
other device that does not have bidirectional communication with the server. 

One way to do it is to set up a generic profile for the device class, which
is activated when the device is activated (e.g. when the device is bought,
through a telephone call to the provider - the same way as is done with
pagers now). The WAP Forum Push group has been working on this (using
CC/PP), but there are some other problems with push media that also need to
be adressed (e.g. caching) that it is not clear how to solve.


At 10:53 1999-03-08 +0100, Philipp Hoschka wrote:
>Date: Sun, 07 Mar 1999 14:53:09 -0800
>To: (WWW TV List)
>From: "Michael A. Dolan" <>
>Mime-Version: 1.0
>Subject: HTTP server driven content negotiation
>X-Mailing-List: <> archive/latest/302
>Precedence: list
>Content-Type: text/plain; charset="us-ascii"
>Content-Length: 731
>When making content-based system profiles, it would be handy to tag
>broadcast content.
>As best as I can tell, CC/PP and the IETF conneg work is not suitable since
>it requires the client to first describe its profile (which cannot
>generally be done in TV).
>HTTP 1.1 has the Vary tag and the concept of server driven content
>negotiation.  However, I found the use of the Vary tag somewhat vague.
>Anyone have any experience with this tag?  Is there more info somewhere at
>W3C on this - from the HTTP 1.1 author perhaps?
>Thanks for any pointers.
>	Mike
>- ------------------------------------------------------
>Michael A. Dolan, Representing DIRECTV,  (619)445-9070   
>PO Box 1673 Alpine, CA 91903        FAX: (619)445-6122
>------- End of Forwarded Message

                     Johan HJELM
       Ericsson Research, User Applications Group 
         Currently visiting engineer at the W3C
             The World Wide Web Consortium
    Fax +1-617-258 5999, Phone +1-617-263-9630
   MIT/LCS, 545 Tech. Sq. Cambridge MA 02139 USA 
        opinions are personal, always my own, 
  and not necessarily those of Ericsson or the W3C.