Research And Design Of Behavior Model Of Reconfigurable Switching System Based On Crossbar Architecture

With the rapid development of network technology,routing and switching systems become very complicated.Whether the performance of a switching system can achieve the expected effect needs to be evaluated by behavioral model simulation,which can be used as a preliminary verification of system correctness and has certain application value.In the process of switching cell system design,the algorithm and architecture model are firstly established by software.And then,the hardware architecture performance of switching unit is evaluated according to the simulation results.The RTL code is written according to the design requirements.Therefore,it is a very important step to establish the behavior model of switching cell system.Therefore,the behavior model is also known as the "Gold Model".In this thesis,the Crossbar-based exchange unit architecture is adopted,based on the comparison of various exchange structures.For the backbone network in the current communication network,combined with the functional requirements of 100 Gbps reconfigurable switching system architecture,this paper analyzes the crossbar switching system architecture,designs and implements a behavior model of 100 Gbps line speed reconfigurable switching system.According to the data flow,it is divided into various sub modules,and then the model is established according to the function independent design,including input and output interfaces,specific function,data format,data storage and so on.The system behavior model is mainly composed of input scheduling,flow classification,packet processing,look-up table,queue management,crossbar switching network and output polling scheduling.Among them,the flow classification module can effectively identify the key segments matching ETH＿SRC,ETH＿DST,IPv4＿SRC,IPv4＿DST,IPv6＿SRC,IPv6＿DST in Open Flow 1.5,and can configure the reconfigurable switching unit system according to individual needs;The packet processing module can receive the control bus data frame and extract some key fields of the data frame to realize packet forwarding;The lookup table module is to find the destination address of the data frame and judge which port to forward;The queue management module is to perform queue in and queue out operations on data frames,coordinate and manage data frame packets sent to different destination ports;The scheduling algorithm module supports the switching of common scheduling algorithms such as SP,RR,WRR,lqf and OCF;The main function of crossbar switching network and output scheduling is to cache and poll the output data frames.Build the system behavior model verification environment,design the network protocol data generation model and performance statistics model,and evaluate the performance of the switching system architecture under the scenarios of deterministic service distribution and uniform service distribution through the simulation verification of the system behavior model.Finally,a parameterized graphical user interface is developed based on the behavior model of switching cell system,which can efficiently evaluate the performance of hardware system.Through the deterministic business distribution simulation test and uniform business distribution simulation test,the functional correctness of this system behavior model is verified,and different scheduling algorithms are simulated and analyzed.The simulation results show that the simulation model can accurately and effectively simulate the internal data processing flow of the 100 Gbps reconfigurable switching system.And it can quickly evaluate the architecture performance of the switching unit.This thesis completes the verification of the correctness of the chip behavior-level system model,which can better guide the work of the early chip design and debug,and help the subsequent software and hardware co-design.The behavior model of the switching system designed in this thesis has been applied and validated in XDNP SOC.