Distribution CPG Protocol

[Stephen Thomas <stephen.thomas@transnexus.com>]

Perhaps we haven't heard enough opinions expressed, but does the following 
summary sound like the current status/consensus?

Is there consensus that the distribution protocol operates in three phases?

   1. CDN advertises its capabilities
   2. The Content Provider requests the use of CDN services by identifying 
content to be distributed.
   3. The CDN confirms (or denies) the request for service

Drilling down, I don't (yet) sense a consensus on all the details, but are 
these all the attributes proposed for phase 1?

   1a. footprint (expressed as a set of IP address prefixes)
   1b. cost
   1c. content type supported
   1d. performance
   1e. generic metric
   1f. load measure
   1g. cache capacity (I'm generalizing from "max file size")

For phase 2, are these the set so far?

   2a. URI path
   2b. Authoritative Source (generalized from "Content AS")
   2c. "next hop" (I don't understand this attribute, so I may be 
mis-characterizing it)
   2d. "metric" (ditto)

I'd also suggest adding

   2e. unique content identifier (e.g. ETag + source ID)
   2f. content size
   2g. generic content attributes (e.g. HTTP entity header values)

Phase 3 could be pretty straightforward. The simplest approach would be a 
binary ACK/NACK, but there might be some value in a bit more fine-grained 
response. Just to get the discussion started, here are some possibilities 
off the top of my head.

   3a. accept/reject
   3b. time frame of commitment
   3c. partial acceptance (e.g. only 10 GB of the 50 GB requested)


If we have a consensus on the three-phase approach, perhaps some discussion 
on the details would be helpful.

Stephen





____________________________________________________________________
Stephen Thomas                                       +1 770 671 1888
TransNexus, Chief Technical Officer    stephen.thomas@transnexus.com