Cisco, Checkpoint, Draytek, and OpenVPN. Or to put the question more precisely and avoid potential misunderstandings on my part:
What is meant by "interoperates" in "Cisco interoperates with Checkpoint interoperates with Draytek interoperates with OpenVPN"?
In my world, "interoperate" in this context would mean something like "a client from one company can connect to a server of the other company". But clearly, that's not what is meant above since only an OpenVPN client can connect to an OpenVPN server (don't know about the other ones).
Stefan