Design,Implementation And Application Of Programmable WiFi Network Based On Protocol Oblivious Forwarding

The rapid development of Mobile Internet has led to a continuous traffic increase in WLAN,and the node-oriented distributed management method in traditional WiFi network system is facing not only more and more serious management complexity but poorer transmission reliability,thus is difficult to apply to large WiFi network.SDN is a new type of network architecture which decouples the control plane and the for-warding plane.It translates the underlying network devices into forwarding pipelines for the purpose realizing programmatically flexible configuration of the data plane.The architecture of Software-Defined WLAN is formed by extending the SDN into the WiFi network,which helps simplify the design and deployment of WLAN.The existing Software-Defined WLAN system implements the data plane using a hybrid method based on OpenFlow with dedicated proxy,which reduces the program-ming capability of WiFi network but brings difficulties in hardware implementation.In this paper,we design and implement a new Software-Defined WLAN system named Po-Fi based on POF which proposed by Huawei.Po-Fi implements the data plane us-ing POF switches,a physical AP is regarded as a general-purpose forwarding pipeline with a multi-stage flow tables,and data forwarding process is performed according to the flow table rules delivered by the control plane,which gives network administrators great programming capabilities.In addition,Po-Fi implements unified management of terminal devices by introducing the concept of a virtual AP to simplify the connection between terminal devices and the physical AP.In Po-Fi,multiple subflows between terminal devices and the remote server are transmitted via different physical APs,by implementing the multi-AP coordinated transmission mechanism based MPTCP.The reliability of data transmission in Po-Fi network system is effectively increased,as data transmission is prevented from passing through the failed physical AP,by means of the sub-flow scheduling of terminal devices itself.Finally,we transplant Po-Fi prototype to commercial routers,build a test bed in a real environment for a series of functions and performance tests.We also show a multi-AP coordinated transmission instance of Po-Fi network system.The experimental results demonstrate the feasibility of Po-Fi and the reliability of multi-AP collaboration mechanism brings for Po-Fi network.