Design And Implementation Of A SDN Controller For Data Center Networks

With the arrival of the era of cloud computing and big data, resources of computing and storage applications on the internet are increasingly migrating towards data centers. Therefore the data centers are becoming huge in size, complex and require high performance of computing and storage. Network management complexity increases rapidly due to the lack of global resource scheduling capabilities, challenges of scalability, robustness and efficiency. These traits are highly desirable from a data center. Software defined network decouples control plane from data plane, puts control on data plane through a centralized controller. Control plane holds the whole information of data plane resources and has a global perspective to allocate network resources. Implementing SDN architecture in data centers and using its advantage to solve existing proble ms of data centers has a bright future.This thesis focuses on realizing an SDN controller application to achieve the goal of centralized management with functions like allocating network resources and network management to satisfy the requirements of a data center. The controller monitors the underlying network resources and selects path for flows based on the information from the data plane. It dynamically adjusts the allocation of network resources, if required. It routes the flows compared with hosts and it copes with the network faults. It puts control on flow traffic and provides a user interface of data plane. The main work is as follows: 1) Analyze the problems of current network architecture of data center and explore the potential benefits of using SDN and Open Flow technology to resolve data center problems; 2) To determine the requirements of the functions of the SDN controller like routing, load balancing, dynamic routing, fault tolerance, traffic control to achieve the aim of resource allocation and network management. Corresponding solutions are given from the perspective of OpenFlow and the relevant functions are implemented in the SDN controller along with user interface. 3) Demonstrate the functional and performance testing for the controller. The functional testing of the controller is achieved by building simple network scenario prototype using OpenFlow switches. The function expansion is achieved by modifying the simulation source codes of Mininet network emulator. The performance of data center network under the management of SDN controller is tested.This thesis implements an SDN controller application to solve problems in current data center. The results through functional and performance testing show that the data centers under the management of SDN network controller can resolve the problems and network throughput and link utilization can reach up to 80% of the ideal value.