PTP Notification Status Conditions

The PTP status notifications are derived based on the following conditions:

PTP Lock State

Clock Status

Status

Description

Freerun

Clock is out of sync state

  • If portState is not “SECONDARY” or ClockClass value is NOT “6”, “7”, “135” or timeTraceable flag is FALSE.

  • If holdover time exceeds its provided value.

  • If PMC, ptp4l.conf, or ptp4l are not accessible.

Locked

Clock is in sync state

  • If portState is “SECONDARY” and ClockClass value is “6”, “7” or “135” and timeTraceable flag is TRUE and PMC, ptp4l.conf, ptp4l or phc2sys are accessible.

  • Locked clockClass values can be changed using the ptp4lClockClassLockedList Helm override. See “Install PTP Notifications” document for instructions.

Holdover

Clock is in holdover state

  • For NICs using the Intel ice driver: If the state is transitioned from Locked to Holdover AND phc2sys is accessible, and holdover time does not expire.

  • For other NIC types: If the state is transitioned from Locked to Freerun AND phc2sys is accessible, and holdover time does not expire.

PTP Clock Class

6

T-GM connected to a PRTC in locked mode (e.g., PRTC traceable to GNSS)

  • For additional details on clockClass values, refer to ITU-T standard G.8275.1

7

T-GM in holdover, within holdover specification, traceable to Category 1 frequency source

135

T-BC in holdover, within holdover specification traceable to Category 1 frequency source

140

T-GM in holdover, out of holdover specification, traceable to Category 1 frequency source

248

T-GM or T-BC in free-run mode

255

Slave only OC (does not send Announce messages)

OS Clock State

Locked

Clock is out of sync state

  • phc2sys is running and disciplining the os clock

  • OS clock is within 1000 ns of 37000000000 expected offset from PHC

Holdover

Clock is in holdover state

  • Holdover timer has not expired

  • phc2sys is not running and not disciplining the os clock

  • OR os clock offset is outside of range

Freerun

Clock is in freerun

  • Holdover conditions met but holdover timer has expired

GNSS State

SYNCHRONIZED

GNSS data is present

  • ts2phc is running and disciplining NIC PHC

  • NIC driver DPLL reports GNSS state is locked

FAILURE-NOFIX

GNSS data is not detected

  • ts2phc is not running, NIC PHC is not being disciplined

  • NIC driver DPLL reports status other than locked

Overall Sync State

Locked

Overall state is locked

  • All monitored services are Locked or Synchronized (excluding clockClass)

PTP Lock State

Holdover

Overall state is in holdover

  • One or more monitored services are in a degraded state (holdover or freerun)

  • Overall sync state holdover time has not expired

Freerun

Overall state is freerun

  • One or more monitored services are in a degraded state (holdover or freerun)

  • Overall sync state holdover time has expired