Research On Resources Allocation Based On Large-capacity SDN Access Network

At present,the access network still has several problems such as insufficient integration with the backbone network,high operation and maintenance costs,lack of flexible heterogeneous network resource scheduling management mechanism and lack of effective end-to-end service quality guarantee mechanism.In order to meet the needs of future access networks with high bandwidth and easy network update and control by management personnel,so the access network and other heterogeneous networks can be easily integrated and controlled,a method to modify the access network is proposed,which uses SDN to improve the controllability of the network and utilize SDN and virtualization technologies to improve access network resource allocation.The thesis first analyzes the relevant research status.Then it puts forward the design of access traffic perception module and the overall access system framework and its implementation is proposed.Finally,the functions of the module and system are tested through simulation experiments.The main work and innovations of the thesis include the following aspects:(1)The traditional QoS service mechanism is reproduced on the Open Flow protocol.(2)By combining the active and passive measurement methods,the thesis innovatively proposes a traffic sensing method based on the Open Flow multi-level flow table.The method solves the problem that the measurement overheads is too large due to the long waiting time of Flow Sense method in the long-term surviving flow scenario and solves the problem that the Open TM method cannot recognize the short-term surviving flow.And the multi-level flow table is used to solve the problem that the matching-based measurement method fails when the matching field of the flow entry has a wildcard.(3)The thesis designs a programming model for configuration policy,network virtualization strategy and delivery interface with scalability,meantime,controlling the quality of service can be realized.The controller and command line tools are developed to implement network access admission control,network virtualization control and access QoS bandwidth management function.The indicators are tested to demonstrate the stability of the system.The results of the thesis' s testing of the module and system show that the traffic identification module used for the measurement of the access side can achieve a recognition accuracy of 95.5% with less overhead.The access bandwidth control test results show that the QoS function can work normally,and different bandwidths are allocated according to the change of the delivery policy.The performance of the policy delivery delay performance indicator shows that the system has good stability and scalability for the network administrators.In the case of large-capacity large-scale access,the access network is predicted and the service configuration is postponed.The thesis work has achieved all the indicators test,and can meet the design and use requirements in performance and function.