Re: What is CONTENT?

[Christophe Deleuze <deleuze@ActiVia.net>]

> From: Fred Douglis <douglis@research.att.com>

> >Hilarie raises an interesting question: Does the "Direction System" need
> >to parse the http headers to get more information in order to direct the
> >request to a correct surrogate?
> 
> This should probably be supported, though everything we've done so far
> at just the DNS level has not done that -- instead, one would have
> to embed that sort of info in the DNS name, e.g. images.foo.com versus
> streaming.foo.com.


I think the direction system clearly needs some information about the type
of data to be delivered:

 - a given machine cannot provide all kinds of service.  Thus, a CDN may
   have to include content specific surrogates (e.g. one for static web, one
   for dynamic web, another for streaming...)  The direction system would
   need content type information to choose the surrogate.

 - moreover, a CDN can provide different reach and/or scale to different
   traffic types (e.g. streaming probably needs more reach than web).

DNS based redirection works for any present or future application, even if
proprietary.

Although people often make a 'content-aware'/'DNS-based' partition of the
direction systems, DNS based redirection can also be content-aware.  It's
simply a matter of including the content type in the domain name.  This is
actually already widely in use today (most web servers are named
'www.something.tld').

Such 'typed domain names', can be useful for a CDN direction system but even
more for a direction peering system, where content type information must be
exchanged.

Such a name space would need to be agreed upon by all peerings CDNs.

-- 
Dr. Christophe Deleuze		Christophe.Deleuze@ActiVia.net
ActiVia Networks		http://www.activia.net