基于时间敏感网络的PTP交换机技术研究

Research on PTP switch technology based on TSN

基于时间敏感网络设计的高精度时间同步系统是目前工业互联网、大数据科学等领域的硬件基础之一。由于传统交换机在标记报文时间戳时无法避免网络栈内部的延迟和不确定性,为了实现更高的时间同步精度和稳定性,基于EVB-KSZ9477S PTP交换机并借助OK335xS开发板辅助控制,设计实现了PTP时间同步系统。该系统采用硬件辅助标记报文时间戳,计算消除PTP帧在网络栈内的不确定性误差,通过内部修正,从而实现较高的时间同步精度。结果表明,相较于普通交换机,基于TSN的PTP交换机的时间同步系统可实现±20 ns以内的时间同步精度和更低的抖动,具有良好的时间同步性能。

The high-precision time synchronization system designed based on the time sensitive network is one of the hardware foundations in the industrial Internet,big data science and other fields.Because the traditional switch cannot avoid the high delay and uncertainty in the network stack when marking the message timestamp,in order to achieve higher time synchronization accuracy and stability,a PTP time synchronization system is designed and implemented based on the EVB-KSZ9477S PTP switch and assisted by the OK335xS development board.The system uses hardware to mark the message timestamp,calculates and eliminates the uncertainty error of PTP frame in the network stack,and achieves high time synchronization accuracy through internal correction.The results show that the time synchronization system of PTP switch based on TSN can achieve time synchronization accuracy within±20 ns and lower jitter compared with ordinary switch,and has good time synchronization performance.