RE: Provider Independent addressing usage

["Tony Hain" <alh-ietf@tndh.net>]

Tony Li wrote:

> I think a very important question is about whether or not 
> exchanges are part of the natural economically incented 
> growth of the Internet.  What we've seen in the US is that 
> they made some sense for awhile, but that private interconnect 
> is drawing the traffic away.  One then has to ask how this 
> architecture will play out given an underlying private 
> interconnect architecture. 

Actually what you have seen in the US is the natural tension between captivity and openness play out. With the possible exception of the CIX, the exchanges in the US have always been about lowering interconnect costs to open the playing field to the small operator, and that is economically contrary to the large operators interests. Yes the big players want to lower costs, but their mechanism is to make the little guys become customers and pay for the private interconnects.

> If one can get better (i.e., more reliable, higher bandwidth)
> service by being in PA space and relying on that provider's
> private interconnect, why then would anyone want to be in PI 
> space?  For those places where exchanges do not currently 
> exist, it seems unlikely that the creation of a routing 
> architecture would cause those exchanges to come into being.  
> And for those places where exchanges already exist, wouldn't 
> most customer trend away from PI space?

If one trusted that single provider to be reliable and fast, they should in fact be in PA space. The counter question is; why would one want any association with a provider's address space when that trust does not exist? Customers are trending away from the traditional defined PI space in IPv4 simply because it is hard to get. At the same time the routing table growth shows they are in fact trending toward PI as an architecture, by requiring the PA space to be hacked up.

A routing architecture by itself will not cause exchanges to be built. What will cause them to be built is a demonstrable business model that shows it is cheaper to go that route than to fight with the instability of the current bloat. Something I sent in a related private thread:

The only way I see anything new being deployed is for someone to sit down with real data and show a sustainable business model that actually lowers overall costs. That exercise in itself is substantial enough that nobody will take it on unless there is general consensus that there is sufficient potential in the approach, and that its scope is bounded and understood. 

The reason I have been persisting on this is that I think we can bound this approach, and it is simple to understand and deploy. I am explicitly trading off efficiency in the address consumption for simplicity in the derivation and routing, as well as trading off maximal routing efficiency for end-to-end system level efficiency. 


> The meta point here is that whatever architecture is selected, 
> it needs to operate with the natural economic order.  Otherwise
> carriers and customers will both be incented to circumvent the
> architecture to optimize their own benefit.

Since those perspectives on 'optimal benefit' are in direct conflict, circumvention will happen in any case. The real question is can we define an architecture that limits the need to circumvent it to accomplish each party's goals? Or when it is circumvented, contain the damage. 

Tony