design of a real routing v. endpoint id seperation

One way to do this is for two ISPs to band together
in order that each ISP can sell half of a joint
multihoming service. Each ISP would set aside a
subset of their IP address space to be used by many
such multihomed customers. Each ISP would announce
the subset from their neighbor's space which means
that there would be two new DFZ prefixes to cover
many multihomed customers.

Each multihomed customer would run BGP using a private
AS number selected from a joint numbering plan. This
facilitates failover if one circuit goes down but
doesn't consume unneccesary public resources per customer.


I've heard of this from others as well. It seems to be technically feasible, but I am curious about the social aspect: would ISPs actually do this? Would customer's find it acceptable? (given it still locks them to an ISP, now to two of them.)

In fact, this is technically feasible right now with IPv4. Does anyone know of a pair of ISPs doing this?


"technically feasible" and "business case reasonable" are two different things.

Under what conditions does this sort of cooperation with a competitor make sense?

When your customer demands it and is willing to either pay for it or stop paying you for anything.

As a customer, I would prefer to multi-home between ISPs who rarely talk to each other rather than those who are in collusion. From a technical perspective I want the operator-induced failures in each ISP to be as independent as possible; from the business perspective I want them both to fight for my money.