Research And Implementation Of Resilient Control Mechanism For Network Resources Based On SDN

With the rapid development of technology,different types of application scenarios are increasing.The motive force of the network development has gradually changed from technologies to applications.Diverse application scenarios generate diverse QoS requirements,although the QoS guarantee mechanism under the traditional network architecture can guarantee the QoS requirement of the application scenarios to some extent,it is limited by the tight coupling of the network devices,and there are problems of difficulty in deployment and poor scalability.Then,researchers have conducted related research based on the next-generation network architecture.With the appearance of software-defined networking(SDN),SDN has the advantage of flexible control of resources by separating the control plane from the data plane of network devices.However,the existing SDN-based network resource control mechanisms aim at the application scenario QoS guarantee or improve the network resource utilization,and lacks the balance of both.In addition,In the face of unexpected traffic,Because of the lack of good network resources adaptive adjustment capability and can not provide effective QoS guarantee.Thus,this thesis focuses on the problems of resource control mechanism and carries out related research on the SDN-based elastic control mechanism for network resource.The main work includes the following aspects:(1)Propose an elastic control model of network resources based on SDN.Firstly,according to the QoS requirements of different application scenarios,the underlying network is divided into several slices.Then,based on the constructed slice,resource adaptive adjustment based on the network state is performed.Under the premise of ensuring QoS requirements in different application scenarios,the utilization of the underlying resources is increased as much as possible.(2)Propose a network slicing method for QoS requirements of application scenarios.In order to guarantee the QoS requirements of different application scenarios,paths that meets the QoS requirements are calculated in advance for each type of application scenario with the same QoS requirements,so as to construct a network slice.In order to improve the reliability of network transmission,multiple transmission paths are sought as much as possible during the construction of the slice.Finally,by using the multi-queue feature of the OpenFlow switch port,the slice are deployed on the OpenFlow switch and the flow table is pre-issued to achieve resource reservation.(3)Propose an adaptive dynamic adjustment method for network resources based on network state.First,when the reserved resources can meet the QoS requirements of the application scenario,in order to improve the utilization of network resources,the usage of network resources in each slice is periodically monitored.If the load of the default transmission path exceeds a certain threshold,the new arrival traffic on the path is selected and scheduled to the lightest load path.The flow table is reissued to realize adaptive adjustment of resources in slices.Secondly,when the reserved network resources will soon not meet the QoS requirements of the application scenario,that is,if the remaining resources of all the paths between source destination nodes in the slice are lower than a certain threshold.In order to deal with possible burst traffic,the dynamic adjustment of resources between slices is performed in advance,and the queues are reconfigured according to the results of resource adjustment,so as to realize adaptive adjustment of resources among slices.In summary,this paper proposes an SDN-based network resource resilience control mechanism.Finally,through a series of simulation experiments and prototype system design and implementation to verify the effectiveness and feasibility of the proposed method.