RE: PI/metro/geo [Re: The state of IPv6 multihoming development]

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

J. Noel Chiappa wrote:
>     > From: Brian E Carpenter <brian@hursley.ibm.com>
> 
>     >>> E.g. if a (large enough) bunch of customers band 
> together and create
>     >>> an exchange, which buys service from multiple ISP's, 
> and which is
>     >>> given an address which is visible over the same scope 
> as those ISP's,
>     >>> and the customers are addressed as part of that 
> exchange, you meet
>     >>> the policy goal (being able to change providers) 
> *without* so-called
>     >>> "PI" addresses. But the addresses are still 
> connectivity-based.
> 
>     > The problem with this (and the reason I have serious 
> doubts about
>     > Tony's PI proposal, and all geographical proposals 
> going back at least
>     > to Bill Simpson's metro proposal years ago)
> 
> Well, you usefully point out that all geographical proposals 
> basically amount to the proposal to create exchanges! :-) At 
> least, if the routing is to remain functional!! :-) :-)
> 
> 
>     > is
>     >  There is no economic reason to create such an exchange.
>     > If we could get past that, of course it works.
> 
> Ah. You misunderstood the point of my comment, which was not 
> to advocate the creation of exchanges, but solely to point 
> out that the terminology of "provider-independent" is not 
> technical terminology, but rather economic/policy terminology.

We don't need to create exchanges, there are already over 200 located in
the global population centers. The economic incentive that is missing is
the motivation for providers to connect to them. Routing table growth
might become enough of an economic burden to cause that. Unfortunately
we are paralyzed by the fear that it will, while refusing to pay what it
will take to avoid it.

Tony

> 
> In other words, there are addressing scheme which are 
> "provider-independent" but which differ in extremely 
> important technical ways from the PI addresses proposed by 
> various people.
> 
> 
> The important division in addressing schemes is between 
> "connectivity-based" and "non-connectivity-based", and it 
> occupies the same place in networking discussions as the 
> division between "second-law-machines" and 
> "perpetual-motion-machines" does in engine discussion.
> 
> There are many useful finer subdivisions of the 
> "connectivity-based" class (e.g. hierarchical, 
> provider-dependent, exchange-dependent, etc - some orthagonal 
> to each other), just as there are many useful finer divisions 
> of the "second-law-machines" class. However, at least in 
> discussion of engine designs one normally doesn't have to 
> spend a lot of time discussing perpetual-motion machines; 
> everyone involves understands that although that is the most 
> fundamental division, the second class isn't worth 
> discussing, and not a lot of time gets spent discussing 
> things in that division.
> 
> One day the networking world will get there too, and the only 
> discussion of routing-names (i.e. those 
> names/identifiers/whatever which the routing calculations use 
> - addresses, in the IPv4/6 architecture) which people will 
> bother with are the "connectivity-based". I'm not holding my breath.
> 
> If people don't like some of the properties that being 
> connectivity-based induces in routing-names, then the answer 
> is simple: define another namespace which has characteristics 
> you like better, and map back and forth between the two.
> 
> If the price of that is too high, then you just have to deal 
> with the hassles of connectivity-based names, just like we 
> have do live with the hassles of friction, entropy, etc.
> 
> 	Noel
>