A Novel IEEE 1588 Synchronization Mechanism for Data Center Time Synchronization Based on the Original Path Return Method and Minimum Delay Packet Screening Algorithm

In order to solve the problem of the IEEE 1588 (precise time protocol, PTP) path delay asymmetry caused by network congestion in data center time synchronization, this paper proposes a novel PTP time synchronization mechanism based on the original path return method and minimum delay packet screening (MDPS) algorithm. The original path return method utilizes the routing record and source station routing function of the IP protocol to enable the PTP packet to return along the original path, ensuring sufficient conditions for delay symmetry of the forth and back paths. The MDPS algorithm is proposed to select the packets on the same path whose delay is not affected by network congestion, thereby fundamentally eliminating the problem of delay asymmetry of forth and back paths in the case of network congestion. To verify the performance of the proposed mechanism, a simulation of the PTP packet queuing model and PTP time synchronization is conducted. The simulation results show that the uncongested packet can be obtained within 2.2 s. Moreover, the maximum absolute time deviation between the slave and master clocks is reduced by approximately 50 times, and the standard deviation of the time deviation is reduced by about 2 orders of magnitude.