In a software-defined network, a powerful central controller provides a flexible platform for defining network traffic through the use of software. When SDN is used in a large-scale network, the logical central controller comprises multiple physical servers, and multiple controllers must act as one to provide transparent control logic to network applications and devices. The challenge is to minimize the cost of network state distribution. To this end, we propose Distributed ZTE Elastic Network Intelligent Controller (DZENIC), a network-control platform that supports distributed deployment and linear scale-out. A dedicated component in the DZENIC controller provides a global view of the network topology as well as the distribution of host information. The evaluation shows that balance complexity with scalability, the network state distribution needs to be strictly classified.

Decentralized peer-to-peer session initiation protocol (P2PSIP) provides the same services as legacy SIPs such as IMS. However, in relatively open network, the requirement for route efficiency in a complex environment brings about undefined problems. To deploy a controllable P2PSIP network, perfect mechanisms have to be appended, especially in QoS, security, and management. Several proposals for QoS, network address translation (NAT), and interworking have been put forward. In this paper, we propose an integrated architecture for a P2PSIP system as well as a proactive intelligent routing scheme on the media plane used in system. Implementation and simulation show that our solution is suitable for operation and management.