An open communication method between at least two sub-networks using a broker node. Each of the sub-networks has a different routable network addressing scheme. The method comprises receiving a packet for a specific application, the packet includes an application identifier, determining if the packet is to be relayed to another of the at least two sub-networks based upon the application identifier, determining if a node receiving the packet is a broker node, relaying the packet to a broker node if not a broker node and forwarding, by the broker node, the packet to at least one node in another of the at least two sub-networks. The node generating the packet communicates using a first of the at least two sub-networks. A broker node communicates using at least two of the at least two sub-networks via a corresponding routable network addressing schemes for each of the sub-networks.