Design And Implementation Of SDN-based Publish/subscribe System

The best-effort service provided by Internet,allows each kind of data to get network resources through fair competition,but it brings limitations to reliable transfer of Publish/Subscribe system.Software Defined Network(SDN)is a new structure of network,implementing separation of control from data transmission.Physical topology and network traffic can be accessed through OpenFlow,and a series of actions can be executed in flow table.OpenFlow provides flexible technical support to pursuit reliability assurance for Pub/Sub System.Based on current research progress,a solution for Publish/Subscribe system immigration to SDN is designed after much investigation.As to the system administration,management of physical devices and topology is added through interact with SDN controller.Routing subsystem is redesigned to use physical topology instead of logical topology.Topic name is encoded into packet header,which is used to recognize the topic of message and execute output actions in flow table.Routing is implemented based on OpenFlow flow table.Queues of different bandwidth are setted in switch to replace the queues in system nodes.A new queue adjustment schema is designed based on the real-time traffic collected by sFlow,which is used as the feedback.In the new system,more system status information is managed by the system management node,like physical device and topology.Topic matching and priority queue run on switches,which simplifys the system nodes.Independent traffic monitoring and bandwidth adjustment schema make system easy to extend.Easily-extensible OpenFlow experimental network of certain scale is constructed applying mature virtualization technology.Tests results reveal the feasibility and good performance of the system.