1) A company has four branch offices(POPs) around the world, New
York, London, Tokyo and Sydney.
2) This company requires IP addresses for internal use, customer
use, etc.
3) Each POP must be multihomed, with connections to two or more
transit providers.
4) Multihoming must support load balancing in both directions.
5) Each POP has a unique set of transit providers, there isn't one
transit provider that has service at all locations.
6) Transit providers come and go, PA space isn't acceptable.
7) There is no connectivity between each POP at all, everything
between nodes goes over the internet.