Enhanced PTP User Guide (UG1602)

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1.0 English

This file shows how to configure sfptpd to act as a PTP master, using the NTP daemon as the reference:

  • An NTP sync module is instantiated using the sync_module option:
    • The key-id and key-value are set for authenticating with NTP using the ntp_key option.
  • A PTP sync module is instantiated using the sync_module option.
  • The PTP sync module is configured to act as a PTP master by using the ptp_mode option.
  • The master also has ptp_tx_latency and ptp_rx_latency options that can be used to compensate for latency between the NTP daemon and interface (see PPS Measurements).
  • Any PTP traffic is transmitted using hybrid mode by using the ptp_network_mode option in the generic [ptp] section (see Hybrid Mode).
Note: NTP uses UTC time - not atomic (TAI) time. When sfptpd is configured as a master clock, it uses UTC time. Therefore ensure that the ptp_utc_offset parameter in the sfptpd master config file is set to a value of 0.