Research On Reliability Of Time Sensitive Network Based On Frame Replication And Elimination

In the industrial control network,the real-time and reliability of the network is essential to ensure the safe operation of the system.The IEEE 802.1CB-2017 protocol is a standard for ensuring network reliability in a time sensitive network protocol cluster.The protocol replicates multiple copies of data frames in multiple redundant paths to the destination node.At the data receiving node,a negotiation algorithm selects data frames to prevent the loss of key data frames.Through theoretical analysis,it is found that in the negotiation processing algorithm,there is a lack of restrictions on the key configuration parameter of the sequence number history record table length,which will lead to potential packet loss and security problems.Aiming at improving the packet delivery ratio in the network and increasing the security and reliability of the network,this thesis proposes an optimal configuration scheme for the length of the sequence number history record table.The main work is as follows:1.This thesis analyzes the working principle of the frame replication and elimination mechanism for reliability,studies each functional module and data frame processing algorithm of the mechanism,and summarizes the key configuration parameters of this mechanism,such as the stream handle,sequence number subparameter,and sequence number history record table.The imperfection of configuration parameters is obtained through theoretical analysis.The potential physical and software fault modes is sumerized,and the existing fault tolerance methods is studied.2.An optimal configuration scheme for the length of the sequence number history table in the data frame processing algorithm is proposed.The program aims to improve the delivery rate of key data frames and reduce network failure time.Through the transmission delay difference between the redundant paths in the network,the actual transmission ratio of the traffic and the data frame size parameters,the maximum value and minimum value of the sequence number history record table in the data frame processing algorithm is determined,standardizing the range of length.Theoretical analysis shows that this optimal parameter configuration scheme can effectively reduce the data frames lost in the fault,increase the network data frame delivery rate,and improve the fault tolerance performance of the network.3.The OPNET Modeler network simulation platform is used to build a platform based on the frame replication and elimination mechanism for the verification and testing of network reliability.Designing a fault injection module verifies the fault tolerance performance of the platform for physical and software faults.On this basis,the optimal configuration scheme is tested.The data frame delivery of different length of the sequence number history table is simulated by means of parameterization.The results show that: In the simulation of 5 minutes,under different fault conditions,the optimal configuration scheme proposed in this thesis is 4% higher than the data delivery rate with the default length of 2 in the standard,and the maximum increase is up to 8%,which can effectively reduce the loss of key data frames.