Things are not so clear when we consider other callout services
such as those involving streaming. When we review the
overall architecture we need to consider impacts of other
services with other protocols.
At 05:12 PM 5/4/2001 -0600, Hilarie Orman wrote:
Like an ICAP control protocol? I'd thought of the sideband control
protocols as being possible actions, but only in the context of
proxying, not in a more general sense.
Errh, now are the processing points
becoming part of the box configuration? A proxy is a 4-point proxy-type
box, a mail gateway is a two-point gateway-type box, etc.?
Hilarie
>>> "Maciocco, Christian" <christian(_dot_)maciocco(_at_)intel(_dot_)com> 05/04/01
04:47PM >>>
In the original draft OPES had been targeted at proxies were the 4 points
clearly map well. However OPES might run on devices which are not proxies,
and should allow flexibility in defining processing points (that still
represent the same meaning for all parties).
For example is there a need to allow "side point" which would be used to
control or feed data to a current service running on one of the 4 processing
point ?
> -----Original Message-----
> From: Andre Beck [mailto:abeck(_at_)bell-labs(_dot_)com]
> Sent: Friday, May 04, 2001 1:26 AM
> To: Rajnish Pandey
> Cc: Hofmann(_at_)bell-labs(_dot_)com; ietf-openproxy(_at_)imc(_dot_)org
> Subject: Re: Processing Point
>
>
> Rajnish,
>
> > Suggestion : We can put such rules at point 3. And
> rules at point 3 should
> > be always considered, irrespective of object coming from
> origin server or cache.
> > This would help us in taking advantage of cache.
>
> I think we have to differentiate between services that generate a
> user-specific response and those that don't.
>
> User-specific services usually modify Web objects depending on certain
> user characteristics, for instance if the user's native language is
> German, then all Web pages are translated to German or if the
> user's Web
> access device is a Nokia cell phone, then all requested Web
> objects are
> adapted to fit the screen of the user's Nokia cell phone.
>
> The second category of services modify Web objects equally for all
> users. For example, a virus scanning service removes the same viruses
> for all users. Or a bandwidth-saving service may compress all
> Web pages
> with gzip before they get sent to the users.
>
> Rules that trigger services of the non-user-specific kind should be
> processed at processing-point 3 because the service execution
> result may
> automatically end up in cache if the caching proxy decides
> that the Web
> object is cacheable. These cached objects would subsequently be served
> to other users as well.
>
> Rules that trigger user-specific services should be processed at
> processing-point 4. The service execution results at point 4
> could still
> be cached. However, they would be cached by the service itself rather
> than by the caching proxy. The same is true for the retrieval
> of such a
> cached Web object. The caching proxy wouldn't know what
> object to serve
> to the client because it doesn't know the user's characteristics like
> preferred language etc. Therefore this would probably require
> a service
> at point 1 which gets triggered for certain user requestss and would
> then check for a cached Web object that matches the user's
> characteristics.
>
> Comments?
>
> -Andre
>
>
>
Michael W. Condry
Director, Network Edge Technology