Ask HN:Is there a solution for networking , between Cloud service providers?

To get meaningful replies, you need to ask a clearer question.

you can bridge two networks together using a VPN you can use openVPN and also AWS and Rackspace provide dedicated VPN's into their network. We already link rackspace and aws via open vpn it is not as fast as WAN point to point line between the two networks but it does what we need.