Software Service Defined Network: Centralized Network Information Service

Software-defined networking (SDN) is fast evolving as a new paradigm for next generation data networking. In SDN, controller is a central piece of its networks, which provides a logically centralized control of the network. Different from the previous studies on Northbound APIs and Southbound APIs of SDN, in this paper, we propose a service oriented network architecture for east-west network expansions in SDN. In particular, we present the software service defined network (SSDN), a network infrastructure to support east-west network expansion and network services federation across multiple domains. SSDN is based on a highly extensible service computing framework, which differs from the traditional BGP/PCE based inter-domain approaches. We describe the network software-service layer (NSSL) in SSDN, its use cases, its controller and service backup mechanisms, and the new business opportunities under the context of SSDN. It is shown that the proposed approach enhances the development efficiency, enables controller agility, improves scalability, achieves separate life-cycle management, enables inter- and intra-domain communication between different controllers, and enhances the network resiliency.