Re: Advertisement Protocol -- more thoughts

[Eric Dean <eric@crystalballinc.com>]

A URL Exchange Protocol could support summarization like 
url: http://www.blah.com/images/.*
   
On Fri, 5 Jan 2001, brad cain wrote:
> URL Exchange Protocol (proxy case)
> ----------------------------------
> This protocol exchanges a list of urls and a set of metrics with
> each set.  This protocol is used to communicate metrics to proxies or
> transparent proxies.  An example would be a CDN advertising
> 
> "Content AS": 2
> url: http://www.blah.com/images
> nexthop: surrogate 1
> metric: 10
> 
> to a transparent proxy. The transparent proxy can then make a local
> decision as to where to retrieve a given object.   (note: a url
> exchange protocol is also needed for logging and billing though
> different types of information needs to be included)
> 

What about exchanging content capabilities: HTTP1.1, Streaming, max file
size.... with the Feedback/Metric Exchange Protocol

> Feedback/Metric Exchange Protocol (DNS direction case)
> ------------------------------------------------------
> This protocol communicates metrics between CDNs and is mostly useful
> for DNS request direction.  Each CDN exchanges a set of agreed upon
> metrics.  Examples include:
>         1. Overall load measure: ability of CDN to handle requests (very
>            coarse grain metric).  this metric also allows a CDN to
> start/
>            stop requests being routed to it (e.g. on/off).
>         2. Source IP addresses: CDN tells peers which layer-3 addresses
>            it has "coverage" for--common case will be ISP CDN that
> wishes
>            to serve content for users in its own address space.
>         3. Others: ....
> 
> 
> 
> Similarities
> ------------
> In both protocols there is a need to exchange metrics.  However,
> granularies
> of information exchanged are different.  With DNS request peering,
> overall CDN metrics (as well as metrics per domain) need to be
> exchanged.
> With proxy peering, URL granularity may be useful (although the large
> amount of state required to be exchanged will be problematic).  Can we
> have one protocol that exchanges all of these metric types:
>         1. URL metrics:"distance" to url, next hop surrogate, etc
>         2. Domain metrics: metric per DNS domain that a CDN is auth for
>         3. Overall CDN metrics: overall state of CDN, IP prefixes for
>         which a CDN covers
> 
> [[We could use BGP and have different "address type" fields for each?
> (layer-3 analogy: one MBGP session can exchange: ipv4, ipv6 and ipv4
> multicast routes)]]
> 
> 
> Accounting
> ----------
> Another use for the URL exchange protocol is for the accounting and
> billing piece.  A URL exchange protocol could be used between "special
> nodes" in the billing/accounting system to exchange information between
> CDNs as to which URLs they are the authoritative redirection entity for.
> This way the accounting information can automatically get rolled up
> towards the authoritative domain.
> 

Eric Dean
President, Crystal Ball Inc.
W 703-322-8000
F 703-322-8010 
M 703-597-6921