FW: WEBI, CDNP, and OPES

["Mark Day" <markday@cisco.com>]

This is the result of a discussion about the relationship between WEBI, CDNP
(that's us!), and OPES, all proposed BOFs in the upcoming IETF meeting.  The
people proposing the BOFs had to submit a joint explanation to the Area
Directors for the Apps area.

--Mark

Mark Stuart Day
Senior Scientist
Cisco Systems
+1 (781) 663-8310
markday@cisco.com


This is the summary of WEBI/WREC, CDNP and OPES as committed.

Michael Condry
Ian Cooper
Mark Day
Mark Nottingham
Hilarie Orman

----------------------

There are currently multiple proposals for IETF Applications Area working
groups related to Web transport/content distribution; WREC/WEBI, OPES and
CDNP. This discussion proposes deliniations between the groups, in order to
clarify their roles.

Historically, WREC focused on caching and replication. WEBI is proposed to
replace WREC and slightly broaden its scope to include issues of general
import to intermediaries. WEBI work items will be distinguished by being
generic, in that they are not specific to one application domain (such as
content peering or value-added proxies). For example, invalidation
mechanisms and intermediate discovery protocols are of interest in multiple
applications. Note that if requirements for a particular application can not
be met by a general mechanism, it may be appropriate to define an
application-specific mechanism as well. WEBI might produce other groups as
workload requires.

The Open Proxy Services architecture (OPES) allows for services to be
constructed "inside the network", allowing both the overlay of value-added
services and the introduction of a processing model in intermediaries. OPES
work items will be distinguished in that they involve definition and/or
support of value-added services on intermediaries. For example, this may
include a means of vectoring messages to "callout servers" and configuration
and managment of services, but should exclude general content routing
mechanisms.

Content Distribution Network Peering (CDNP) defines a model and mechanisms
for the interconnection and cooperation of networks for content-related
tasks: direction (directing requests for content), distribution (moving
content out to surrogates) and accounting (tracking the delivery of content
from surrogates).  A single network may have its own mechanisms for these
tasks, and WEBI may define or standardize elements of those mechanisms. CDNP
focuses on the interactions required for direction, distribution, and
accounting between two or more networks with different administrations,
where the networks are potentially using different local mechanisms for

Within WREC/WEBI, OPES and CDNP are largely orthogonal. The groups
should cooperate in order to avoid conflicting specifications.