at Monday, December 02, 2002 8:42 AM, Eugen Leitl <eugen@leitl.org> was seen to say:

No, an orthogonal identifier is sufficient. In fact, DNS loc would be a good start. I think what I am trying to say is - given a "normal" internet user using IPv4 software that wants to connect to someone "in the cloud", how does he identify *to his software* the machine in the cloud if that machine is not given a unique IP address? few if any IPv4 packages can address anything more complex than a IPv4 dotted quad (or if given a DNS name, will resolve same to a dotted quad)

The system can negotiate whatever routing method it uses. If the node doesn't understand geographic routing, it falls back to legacy methods. odds are good that "cloud" nodes will be fully aware of geographic routing (there are obviously issues there though; given a node that is geographically "closer" to the required destination, but does not have a valid path to it, purely geographic routing will fail and fail badly; it may also be that the optimum route is a longer but less congested (and therefore higher bandwidth) path than the direct one.

For a mental image, imagine a circular "cloud" with a H shaped hole in it; think about routing between the "pockets" at top and bottom of the H, now imagine a narrow (low bandwidth) bridge across the crossbar (which is a "high cost" path for traffic). How do you handle these two cases?