Subject: WG Review: Content Distribution Internetworking (cdi)

From: The IESG <[email-masked]>
Date: Mon, 30 Jul 2001 17:15:25 -0400

A new IETF working group has been proposed in the Applications Area.
The IESG has not made any determination as yet. 

The following Description was submitted, and is provided for
informational purposes only:

Content Distribution Internetworking (cdi)
------------------------------------------

 Current Status: Proposed Working Group
 
Description of Working Group:
 
The goal of this working group is to define protocols to allow the
interoperation of separately-administered content networks.

A content network is an architecture of network elements, arranged for
efficient delivery of digital content. Such content includes, but is not
limited to, web pages and images delivered via HTTP, and streaming or
continuous media delivered via RTSP.

Caches and caching systems have been deployed for a number of years.  
More recently, a number of CDN (content distribution network or content 
delivery network) services have been built and offered commercially. In 
addition, a number of hardware and software vendors have developed 
products that enable the construction of CDNs or CDN-like systems with 
"off-the-shelf" parts. The proliferation of content-networking 
capabilities gives rise to interest in interconnecting these systems and 
finding ways for separately-administered networks to cooperate for 
better overall service.

A content network has some combination of a request-routing system, a
content-delivery system, a distribution system, and an accounting 
system. In some cases, such a "system" may be implemented by very simple 
components or techniques.

- The content-delivery system consists of a set of "surrogate" servers
  that deliver copies of content to sets of users.

- The request-routing system consists of mechanisms that move a client
  request toward a rendezvous with a surrogate.

- The distribution system consists of mechanisms that move content from 
  the origin server to the surrogates.

- The accounting system records and aggregates information necessary for
  allocating costs. An effective content network arranges the 
  request/content rendezvous to take place at a surrogate that is "well 
  suited" to a given client. Some content networks may use IP multicast, 
  satellite distribution, and/or application-layer multicast as part of 
  their implementation, but none of these specific technologies is 
  required in a content network.

The working group will first define requirements for the three kinds of
content internetworking: interoperation of request-routing systems,
interoperation of distribution systems, and interoperation of accounting
systems.  These requirements are intended to lead to a follow-on effort 
to define protocols for interoperation of these systems.

In its initial form, the working group is not chartered to deliver those
protocols, but we encourage individual submission of internet-drafts
describing protocols intended to meet the evolving requirements.  We
anticipate rechartering of the working group to specify protocols, after 
the requirements documents are stable and rough consensus emerges about 
the number and relationship of such protocols.

In addition to defining requirements, the working group will develop a
number of supporting documents.  These documents are: a shared 
vocabulary for the problem domain, scenarios, an overall architecture 
for interoperation, and a summary of request-routing mechanisms 
currently in use.  The total expected deliverables are as follows, along 
with notes indicating the drafts that are a start on each document:

1. Vocabulary
        (Merged from day-cdnp-model and rzewski-oacp)

2. Scenarios
        (Merged & enlarged from day-cdnp-scenarios and rzewski-oacp)

3. System Architecture
        (Merged from green-cdnp-gen-arch and rzewski-oacp, requirements 
         moved out to appropriate requirements documents)

4. Request-Routing Known Mechanisms
        (finish cain-cdnp-known-request-routing)

5. Requirements for Request-Routing
        (finish cain-request-routing-req, merging in part of
          green-cdnp-gen-arch)

6. Requirements for Distribution
        (finish amini-cdi-distribution-reqs, merging in part of
        green-cdnp-gen-arch and rzewski-cndistcs)

7. Requirements for Accounting
        (finish gilletti-cdnp-aaa-reqs, merge requirements from
         rzewski-cnacct)

=========================================================

Note: If approved, the following Internet-Drafts will becomne WG 
documents:

draft-day-cdnp-model-06.txt
draft-day-cdnp-scenarios-03.txt
draft-gilletti-cdnp-aaa-reqs-01.txt
draft-green-cdnp-gen-arch-03.txt
draft-cain-cdnp-known-request-routing-02.txt
draft-cain-request-routing-req-01.txt
draft-amini-cdi-distribution-reqs-01.txt
draft-rzewski-oacp-00.txt
draft-rzewski-cndistcs-00.txt
draft-rzewski-cnacct-00.txt
draft-deleuze-cdnp-dnsmap-peer-00.txt