[address-policy-wg] Policy proposal: #alpha: TLD Anycast Allocation Policy

On Wed, 30 Mar 2005 21:30:38 +0200, Hans Petter Holen wrote:
>I agree that IPv6 needs multi-homing to fly - but I was hoping there 
>would be other technical implementations of multi-homing than PI.
It seems we need a thing called "wonder".

Call it PI, Prefix or whatever, here is what we have:
- A *arbitrarily* connected set of nodes - called AS'es- in a graph,
  called "Internet".
- A set of destinations, called "prefixes".
- Things called "packets", which should be routed thru the graph
  on a short (best: the shortest) path.

If one can find a way to route these packets on the shortest path
in any topology without telling the nodes something about each
destination, - even a source route is such information and requires
knowledge about the structure of the graph - he will probably receive
the Fields medal and/or a Nobel price ;-/

The original idea behind the IPv6 TLA, NLA, SLA was a geographical
and administrative hierachical design, in the century of *competitive*
operators this concept is *broken by design*.

In this competitive network world, where operator A charges B for
transit, the only chance to implement *true* multihoming is to pass
information about the destination to all relevant nodes.

But I don't see why we should have a problem doing so.
Memory is cheap.

However there *are* possible technical improvements,
example given:
- Use a two level address distribution concept:
  Level 1 : Pass path information about ISP AS'es only*
  Level 2 : Flood address origination information separate.

( Example: Multihoming Customer 1 is using AS1 and AS2 for prefix X,
  Customer 2 is using AS2 and AS3 for prefix Y, then a far AS would see
  Level 1 : Paths : (AS5 AS4 AS1), (AS5 AS6 AS7 AS2), (AS3)
  This is sufficient to avoid loops and build policies.
  Level 2 : Offers: AS1:(X), AS2(X,Y), AS3(Y)
  No path information is required in these floods. )

- Pass information on demand
  ( However this should only be done in a two level concept for
    stability reasons, think of "bad weather" DDoS Flood conditions. )

*However* all this solutions have one impact:
-  New BGP protocol, new routers, new budget ...

Ceterum Censeo:
Either there is way to *route* the IPv6 address space, *at least*
*with the IPv4 quality* - which means serving the customer demand
"true multihoming", or IPv6 is dead.

If a large address space is offered, it must be *usable*, which means
*routable*, at least with the capabilities of the good old IPv4.

No one needs a 40 digit ZIP code for letters for a human postman,
a 5 digit code is suffiicient. And a postal service offering 40 digits
ZIP codes as "premium service" for standard letters will probably
economically fail ;-/

Best Regards
Oliver

P.s.: Think of UMTS. Design driven by comissions and managers.
Today: Billions spend. >270ms ping time. B.t.d.t.
Same for IPv6 ?!


Oliver Bartels F+E + Bartels System GmbH + 85435 Erding, Germany
oliver at bartels.de + http://www.bartels.de + Tel. +49-8122-9729-0