Evaluation of synchronization performance with PTP

In this paper, we described time synchronization performances with Precise Time Protocol (PTP). The synchronization experiments between a master clock and slave clocks were performed for two cases, that is, one with direct connection and the other with switches. From the experiments, the followings were observed. In the case of direct connection, actual and average offsets between the master and the slave clocks were under several nanoseconds and path delays were estimated vey stably within a few nanoseconds. However, in the case of using a hub, the offsets were greater than several tens of nanoseconds and the estimated delays were fluctuated severely.