Software-Defined Network Exchanges (SDXs): Architecture, services, capabilities, and foundation technologies

Software Defined Networks (SDNs), primarily based on OpenFlow, are being deployed in single domain networks around the world. The popularity of SDNs has given rise to multiple considerations about designing, implementing, and operating Software-Defined Network Exchanges (SDXs), to enable SDNs to interconnect SDN islands and to extend SDNs across multiple domains. These goals can be accomplished only by developing new techniques that extend the single domain orientation of current SDN/OpenFlow approaches to include capabilities for multidomain control, including those for resource discovery, signaling, and dynamic provisioning. Several networking research communities have begun to investigate these concepts. Early architectural models of SDXs have been designed and implemented as prototypes. These SDXs are being used to conduct experiments and to demonstrate the potentials of SDXs.