New model doc draft available

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

I'm happy to say that a new version of the model document is now available
as
http://www.ietf.org/internet-drafts/draft-day-cdnp-model-06.txt

I am still working on the document -- this is not intended to be the final
word.  In particular various parts of description/examples are still
inconsistent and/or incomplete. However, the definitions seem to be getting
stable enough that it's worth putting this out (after all, "internet-drafts
are *drafts*").

Below is a summary of the changes.  Most of the work has been reconciling
with RFC 2616 (HTTP/1.1), RFC 3040 (the WREC taxonomy), or clearly stating
where there is an intentional difference from those.  There have been a
handful of new terms from the requirements documents, and I have killed off
the various "peering systems" that seem in retrospect to be unused
over-elaborations.  In keeping with a recent conference call among the
document editors, I have started (if not finished) the process of replacing
"peering" with "internetworking" in most contexts.

--Mark

ACCOUNTING ADVERTISEMENT:
eliminated. I don't think this was actually used outside the model.

AREA ADVERTISEMENT:
new term from request-routing requirements.

CLIENT:
1. Added USER AGENT, distinct from CLIENT.
2. Aligned CLIENT with RFC 2616 (clarified similarities/differences).

CONTENT:
made explicit connection to "entity" in RFC 2616.

CONTENT ADVERTISEMENT:
new term from request-routing requirements.

CONTENT DESTINATION:
new term from distribution requirements.

CONTENT INTERNETWORKING GATEWAY (CIG):
replaces CONTENT PEERING GATEWAY (CPG).

CONTENT NETWORK ELEMENT:
new term, taking place of NETWORK ELEMENT.

CONTENT REPLICATION:
new term from distribution requirements.

CONTENT PEERING GATEWAY (CPG):
replaced by CONTENT INTERNETWORKING GATEWAY (CIG).

CONTENT SOURCE:
new term from distribution requirements, replaces DISTRIBUTING CONTENT
NETWORK.

DISTRIBUTING CONTENT NETWORK:
replaced by CONTENT SOURCE.

DISTRIBUTION ADVERTISEMENT:
rewritten to match the usage in the distribution requirements draft.

DISTRIBUTION SYSTEM:
updated to be in terms of CONTENT NETWORK ELEMENT.

NETWORK ELEMENT:
reconciled with RFC 3040.  "Network element" is no longer a special term in
the CDI model, but is used in the same sense as RFC 3040. The new term
CONTENT NETWORK ELEMENT is introduced to take the place of NETWORK ELEMENT.

PEERING:
generally replaced by INTERNETWORKING.

* PEERING SYSTEMS:
eliminated. Most of the documents are written in terms of the functional
systems (RR, D, A) interconnecting via gateways; the "peering systems"
appear to be redundant.

REQUEST-ROUTING ADVERTISEMENT:
eliminated. Added AREA ADVERTISEMENT and CONTENT ADVERTISEMENT instead.

REQUEST-ROUTING SYSTEM:
updated to be in terms of CONTENT NETWORK ELEMENT.

SURROGATE:
Slightly changed description. SURROGATE is still defined differently from
RFC 3040.

USER AGENT:
new term matching the one in RFC 2616.

Descriptive text and examples:
Changed "forward proxy caching" to "caching proxy" in descriptions, in
conformance with RFC 3040 terminology.