Re: Distribution CPG Protocol - Some Thoughts

[Christophe Deleuze <deleuze@ActiVia.net>]

> From: Oliver Spatscheck <spatsch@research.att.com>
> 
> PhaseI: CDN advertise capabilities
> PhaseII: the contenet is advertised to a subsest of CDNs (maybe even
> 	 subset of surrogates within a CDN)
> PhaseIII: the CDN accepts the content advertisment 

Refining this, and based on what we proposed in the "DNS mapping peering
draft" (sections 5.1.1 and 5.1.2), a CDN "delivery capability" could be
defined by the following criteria:

	- delivery service (content type)
	- delivery cost
	- delivery footprint (covered area)
	- ...

Note that with this definition, the delivery capability actually includes
(maybe not explicitly) the definition of which subset of the CDN or of the
surrogates are used in this capability.

Thus the three phases can be rewritten as:

1 - CDN advertises a set of delivery capabilities
2 - content chooses a delivery capability and ask the CDN
3 - CDN accepts or rejects


A delivery footprint could be expressed as a set of Oliver's regions:

> Stephen Thomas writes:
>  > At 10:22 AM 2001-01-05 -0500, Oliver Spatscheck wrote:
>  > >Internally we define a region as:
>  > >
>  > >REGION : <NAME> {
>  > >        <IP>,<PREFIXLEN>;
>  > >        <IP>,<PREFIXLEN>;
>  > >        ....
>  > >}!
>  > 

> My take would be that you can define attributes for regions, with some
> standard attributes like " I own the regions IP address space and have
> proxies " to some attributes which are custom between CDNs. However, it
> would be nice if even those custom attributes could be communicated in our
> framework.

Seems reasonable to me.  A CDN can advertise it covers a region if it is
able to efficiently deliver content to all hosts in this region, i.e. has
"enough" surrogates in it.

christophe

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