Joint Consolidated Middleboxes and Virtual Switch Deployment and Routing for Load Balancing in Software-Defined Network

Network Function Virtualization (NFV) is a rapidly developing network architecture concept, in which virtualization technologies transform network functions in hardware devices to software middleboxes. For reasons such as improving security and performance, flows in the network need to traverse specific service function chains (SFCs). Due to the rapid increases in traffic volume, traffic variety, and service requirements, it becomes much complex for SFC routing. The existing solutions for joint middlebox placement and routing still consume a lot of forwarding rules and result in overloaded controllers, which decrease the scalability of middlebox networks. To solve these problems, this paper proposes a joint deployment scheme, which uses the consolidated middlebox to simplify the processing of SFC and uses the virtual switch (e.g., OVS) to reduce TCAM usage. Specifically, We formulate the joint optimization of consolidated middleboxes and the virtual switch placement, as well as routing (JPR) problem into an integer linear programming model, and prove its NP-hardness. An efficient algorithm is proposed to solve the JPR problem. Extensive simulation results show that the proposed solution can achieve better load balancing while using fewer forwarding rules than other existing algorithms. For example, our algorithm can reduce the maximum flow entries by 69%, and reduce the maximum link load by 45% compared with the state-of-the-art approaches.