// Module included in the following assemblies:
//
// * scalability_and_performance/telco_ran_du_ref_design_specs/telco-ran-du-rds.adoc

:_mod-docs-content-type: REFERENCE
[id="telco-ran-ptp-operator_{context}"]
= PTP Operator

[role="_abstract"]
Configure Precision Time Protocol (PTP) in cluster nodes to ensure precise timing and reliability in the RAN environment.

New in this release::
* Support for PTP boundary clock without holdover on GNR-D hardware.

Description::
Configure PTP in cluster nodes.
PTP ensures precise timing and reliability in the RAN environment, compared to other clock synchronization protocols, like NTP.
Support includes::
* Grandmaster clock (T-GM): use GPS to sync the local clock and provide time synchronization to other devices
* Boundary clock (T-BC): receive time from another PTP source and redistribute it to other devices
* Ordinary clock (T-TSC): synchronize the local clock from another PTP time provider

Configuration variations allow for multiple NIC configurations for greater time distribution and high availability (HA), and optional fast event notification over HTTP.

Limits and requirements::
* Supports the PTP G.8275.1 profile for the following telco use-cases:
** T-GM use-case:
*** Limited to a maximum of 3 Westport channel NICs
**** Requires GNSS input to one NIC card, with SMA connections to synchronize additional NICs
*** HA support N/A
*** GNR-D is not supported for T-GM.
** T-BC use-case:
*** Limited to a maximum of 2 NICs
*** System clock HA support is optional in 2-NIC configuration.
*** GNR-D is not supported for T-BC.
** T-TSC use-case:
*** Limited to single NIC only
*** System clock HA support is optional in active/standby 2-port configuration.
*** GNR-D is not supported for T-TSC.
** T-BC without holdover use-case:
*** GNR-D hardware with 0, 1, or 2 additional Carter Flats, e830 NICs
*** Time receiver port must be one of the onboard NAC ports.
*** Time transmitters may be configured to any combination of NAC and Carter Flats ports, up to a total of 23.
*** Holdover is not enabled, so any failure of the Time receiver will enter `FREERUN` state immediately.
* Log reduction must be enabled with `true` or `enhanced`.

Engineering considerations::
* Example RAN DU RDS configurations are provided for:
** T-GM, T-BC, T-TSC, and BC-without-holdover
** Variations with and without HA
** Variations with and without fast event notification
* PTP fast event notifications use `ConfigMap` CRs to persist subscriber details.
* Hierarchical event subscription as described in the O-RAN specification is not supported for PTP events.
* Cluster nodes must have proper NTP configuration to ensure correct time prior to PTP operator taking ownership of node timing.
