So now we have a partial X and partial Y network, X goes down, and chances are your network got hammered like an icecube in a blender set to Frappe.

If IP networks become the single layer 2/3 telecommunications technology in the world then we can never let that Frappe happen. We will have to find ways to deliberately build networks using vendor X and vendor Y in such a way that the sum total is more reliable than a pure X or a pure Y network. --Michael Dillon