Research On Application-aware Resource Management In Software Defined Networking

Software defined networking(SDN)architecture based on separation of control and data plane in network element enables network programmability and application aware networking.In today's SDN solutions,controllers are able to provide open APIs through service abstraction,applications can invoke connectivity services across multiple domains through these APIs.In this thesis,we point out that resource management in today's SDN implementation is still largely designed for the conventional network management purpose,and the controller is,for the most part,not aware of how applications are using network resources.On the other hand,SDN offers opportunities to develop high-level abstractions for implementing network update,but current SDN controller platform lacks effect mechanisms for updating network configuration on the fly.Network controller can only update one network node at a time.Naively updating individual nodes may lead to incorrect network behaviors.Elegant solution based on two-phase update can guarantee that traffic will be processed consistently during network update,which means each packet can be routed based either on initial network configuration or target network configuration,but never a mixture of the two.However,implementing the consistent network update is expensive based existing two-phase update mechanism.We rethink the structure of resource management in modern SDN controller,and present the design and implementation of hierarchical network metadata structure based on tripartite graph logic.In the proposed structure,the information of how applications are using network resources is recorded,which would meet plenty of application's demands.In terms of network update,our design addresses one major problem: how to delete the initial configuration effectively from network nodes when controller enforces the target configuration.The proposed structure can accelerate the procedure of removing the initial configuration,and help to achieve memory-saving network update.Finally,we describe the results of testbed experiments and simulations demonstrating the performance improvement which the proposed structure brings and the effectiveness of configuration deletion and the effect of memory-saving for the network.