Re: Distribution CPG Protocol

[Oliver Spatscheck <spatsch@research.att.com>]

Stephen, 
Phil,

	 first let me state that I think Phil provides a good summary
in his two emails and personally I feel we are converging to a common approach
(wasn't sure a few days ago).

As to Stephen's comment I think there is value in the exchange protocol. The
perl script approach is harder (and more time consuming) than you thinking.
Getting those things working between the infrastructure of various CDNs to
a point at which you feel comfortable offering it to paying customers takes
time and effort.

In addition I see an entire class of documents coming out of this:

1. Basic exchange document (maybe with a basic 2 phase protocol 
   and an optional 3rd accept phase to accommodate both approaches proposed)
2. A set of documents describing metrics used for the above
   protocol.

This approach keeps the basic protocol simple (Brad's comment) and allows us
to introduce new metrics as need be without complicating the protocol
description. It also gives the power to CDNs to use their own proprietary
metric.

I hope at the end of this process we have at least one document in category
two. This would improve interoperability greatly and as stated in my earlier
emails I think there would be great us for that.  However, I would still feel
successful if we only define the protocol in category one. In addition
separating the two seems to remove a lot of contention.

Oliver



Stephen Thomas writes:
 > 
 > My turn to play devil's advocate.
 > 
 > At 06:00 PM 2001-01-11 -0800, Phil Rzewski wrote: [re attributes of surrogates]
 > 
 > >Indeed, once you've just got a list of numbers, there's really not even a 
 > >need to name them "Bandwidth", "Disk space available"... you've just got a 
 > >list of "Genric Metrics". We certainly CAN think of some metrics that are 
 > >likely to have some use (such as "Bandwidth"), but if we build them into 
 > >the protocol, we'll just be taking up extra space in the event those 
 > >specific metrics aren't used somewhere. Since we can't possible think of 
 > >EVERY metric someone might want to define, we'll need to have a place for 
 > >Generic Metrics anyway. Why not make them all Generic?
 > 
 > At 06:38 PM 2001-01-11 -0800, Phil Rzewski wrote: [re IP address prefixes]
 > 
 > >There's no law that says that the prefixes advertised through CDNP 
 > >protocols need to be the exact same prefixes advertised by the routers 
 > >speaking BGP. I see it as an advantage that someone COULD use the same 
 > >prefixes (especially for the purposes of getting this up and running), but 
 > >they don't have to....
 > 
 > Sounds to me like an argument for just shipping around a bunch of generic 
 > values. If that's the case we can just co-opt, say, SCSP [RFC 2334] and be 
 > done with it. Or maybe the two parties could just hack together a couple of 
 > CGI/Perl scripts and run them on a couple of Linux/Apache boxes. Any 
 > competent CDN operator ought to have folks that could whip that out in a 
 > couple of hours, which is a heck of a lot quicker than waiting for the IETF 
 > to charter a WG, the WG to develop standards, vendors to implement the 
 > protocols, CDN operators to purchase the systems, operators to agree on 
 > their generic metrics, operators to configure their brand new CDN-peering 
 > boxes, etc..
 > 
 > Seriously, though I appreciate Phil's reasoning, it's hard to convince me 
 > that there's any real value in creating a standard protocol that's merely 
 > transporting generic metrics around.
 > 
 > 
 > 
 > ____________________________________________________________________
 > Stephen Thomas                                       +1 770 671 1888
 > TransNexus, Chief Technical Officer    stephen.thomas@transnexus.com
 > 
 >