Research On Reliable Trans-misson Technology Based On P4

With the rapid development of Internet and communication industries,the disadvantages of traditional network architectures are becoming more and more significant,which lacks flexibility and scalability.As a new network architecture,Software-Defined Network(SDN)has become a research hotspot of future networks.Programming protocol-independent packet processors(P4)is a shortly-proposed programming language for the data plane in SDN,which provides a new solution for network design.Network transmission reliability is an important indicator in network design.Network failures that affect reliability are mainly divided into link failures and switch failures,and failure detection and failure recovery are the main effective solutions.The thesis conducts research on this issue.Aiming at how to use the programmable data plane provided by P4,this thesis designs and implements a fast and effective failure detection and recovery mechanism,which focuses on the three problems of blocked links,disconnected links and switch failures.The main contributions of this thesis are as follows:1.For blocked links,this thesis designs and implements a failure detection method based on the link delay provided by P4 and the timing data prediction at the downstream switch,and a fast reroute method based on backup path preplanning and failure information broadcast is proposed for link failure recovery.2.For disconnected links,inspired by BFD protocol,this thesis proposes a failure detection method implemented by the switch.In the method,heartbeat packets are designed to feedback link status and detect disconnected links,which are triggered by time interval of receiving packets on a port.Compared with existing solutions,the method has better real-time performance because it is implemented on the data plane,which reduces the overhead of the control plane.3.For switch failures,this thesis proposes a detection method which adds a reachability response mechanism to the link failure recovery method.The method distinguishes between link failures and switch failures,so different failure recovery strategies will be implemented.The detection accuracy and recall of blocked links are counted,as well as the detection and recovery time in three kinds of failures,which are compared with the results of the traditional SDN method.The results verify the effectiveness and superiority of the solution.