Research On Lightweight SDN Control Platform And Technologies Supporting Multiple Flow Tables

Nowadays the network has become an indispensable part of our daily life.The existing network architecture is large and complex,which leads to increasing complexity of network management.Errors would occur frequently in the process of configuration.With the advent of Software Defined Networking(SDN),the above problems of network will be addressed.SDN is a new network architecture that decouples the control plane and the data forwarding plane in traditional network architectures.After the separation of control plane and data forwarding plane,interactions between these two planes are based the OpenFlow protocol,and the data plane based on the flow table to process forwarding operations.The forwarding mechanism based on flow tables provides programmability for SDN.But with the increasement of network services,the scale of flow tables shows a rapid growth trend in OpenFlow switches.A large number of flow table entries in the switch are difficult to be stored in the limited TCAM in the switch,so it has become a bottleneck in the development of the network.In order to adapt to the dynamically changing network state and simplify the complexity of network management and reduce the number of flow table entries in the SDN switch,this thesis combined with multiple flow table technology proposed by OpenFlowl.1 and classical SDN architecture designs a SDN control platform which supports multiple flow tables.In addition,on the basis of researches in NetCore-M language,this thesis further modifies the syntax and semantics of NetCore-M language.We added a formal description of multiple flow table in NetCore-M language.Besides,based on the research on the combination of network service functions,this thesis proposes a multiple flow table implementation method for network service function combination,which provides the theoretical basis for the multiple flow table implementation in deploying service function chain to network forwarding node.In this thesis,based on the study of multiple flow table,we propose two multiple flow table design schemes in OpenFlow 1.3 protocol respectively:the design scheme of multiple flow table on the basis of the logical relationship between match fields and the design scheme of multiple flow table on the basis of specific values of match fields.Through the conversion of multiple flow table,the number and storage space of the flow table entries in the SDN switch are reduced,and the efficiency of the packet processing is improved.In addition,according to the multiple flow table design scheme,we introduce some appropriate applicable scenes.Finally,this thesis validates the lightweight SDN control platform supporting multiple flow table experimentally,and completes the system verification from the perspective of the multiple flow table design,automatic deployment for multiple flow table and packet processing performance.