TELCODOCS#2607: Configuring a boundary clock without holdover on GNR-D

modules/nw-ptp-granite-rapids-boundary-clock-overview.adoc

@@ -0,0 +1,31 @@
+// Module included in the following assemblies:
+//
+// * networking/advanced_networking/ptp/configuring-ptp.adoc
+
+:_mod-docs-content-type: CONCEPT
+[id="nw-ptp-granite-rapids-boundary-clock-overview_{context}"]
+= Boundary clocks without holdover on Intel Granite Rapids-D hardware
+
+[role="_abstract"]
+Intel Granite Rapids-D (GNR-D) server platforms support Precision Time Protocol (PTP) boundary clock (BC) deployments without holdover for high-density Radio Access Network (RAN) sites that use onboard Network Acceleration Complex (NAC) ports and optional Carter Flat expansion network interface cards (NICs).
+
+In a BC deployment, one time receiver (TR) port synchronizes to an upstream timing source while time transmitter (TT) ports distribute synchronized time to downstream devices. GNR-D platforms use platform-specific `PtpConfig` plugin configurations and internal timing paths.
+
+Before you configure a BC profile on GNR-D hardware, verify that your qualified hardware layout, interface naming, and plugin configuration align with your deployment requirements.
+
+GNR-D BC deployments use onboard NAC ports as the primary timing controller and can extend timing distribution by using optional Carter Flat expansion NICs. 
+
+GNR-D platforms route synchronization internally instead of using external timing cabling. 
+
+Your qualified hardware layout determines the available TR and TT port roles across NAC ports and optional Carter Flat expansion cards.
+
+[id="nw-ptp-granite-rapids-boundary-clock-overview-without-holdover_{context}"]
+== Boundary clock without holdover behavior
+
+GNR-D boundary clock deployments on Carter Flat hardware do not maintain time synchronization if the upstream timing source becomes unavailable. This deployment model operates without monitored holdover because Carter Flat hardware does not expose sufficient follower digital phase-locked loop (DPLL) accuracy information for holdover support.
+
+To maintain synchronization, keep a continuous connection to a qualified upstream PTP source.
+
+Red Hat tools can detect follower DPLL lock state, but they cannot monitor the detailed follower DPLL accuracy that holdover support requires.
+
+When you configure a BC profile on GNR-D hardware that uses Carter Flat NICs, disable holdover.

modules/ptp-configuring-linuxptp-services-as-boundary-clock-gnrd.adoc

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+// Module included in the following assemblies:
+//
+// * networking/advanced_networking/ptp/configuring-ptp.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="ptp-configuring-linuxptp-services-as-boundary-clock-gnrd_{context}"]
+= Configuring linuxptp services as a boundary clock without holdover on Intel Granite Rapids-D hardware
+
+[role="_abstract"]
+Use this procedure to configure a Precision Time Protocol (PTP) boundary clock (BC) profile without holdover on Intel Granite Rapids-D (GNR-D) hardware that uses onboard Network Acceleration Complex (NAC) ports and optional Carter Flat expansion network interface cards (NICs).
+
+In this deployment, one time receiver (TR) port synchronizes to an upstream timing source and time transmitter (TT) ports distribute synchronized time downstream.
+
+[IMPORTANT]
+====
+GNR-D BC deployments that use Carter Flat NICs operate without monitored holdover. Disable holdover in your `PtpConfig` profile.
+====
+
+.Prerequisites
+
+* You have installed the OpenShift CLI (`oc`).
+* You are logged in as a user with `cluster-admin` privileges.
+* You have installed the PTP Operator.
+* You have verified your qualified GNR-D hardware layout, including NAC ports, Carter Flat ports, and TR/TT role assignments.
+* You have verified interface naming and plugin device alignment for your hardware layout.
+
+.Procedure
+
+. Create a `PtpConfig` custom resource (CR) that matches your qualified GNR-D BC without holdover hardware layout:
++
+[source,yaml]
+----
+TBD
+----
+
+. Apply the `PtpConfig` CR:
++
+[source,terminal]
+----
+$ oc apply -f gnrd-bc-config.yaml
+----
+
+.Verification
+
+. Verify that the `PtpConfig` profile is applied:
++
+[source,terminal]
+----
+$ oc get ptpconfig -n openshift-ptp
+----
+
+. Verify that the `linuxptp` daemon is running on the target node:
++
+[source,terminal]
+----
+$ oc get pods -n openshift-ptp -o wide
+----
+
+. Review `linuxptp` daemon logs for BC status:
++
+[source,terminal]
+----
+$ oc logs <linuxptp_daemon_pod> -n openshift-ptp -c linuxptp-daemon-container
+----
+
+. Verify the following:
++
+* The TR port synchronizes successfully to the upstream timing source
+* TT ports distribute timing downstream
+* The deployed BC profile operates without holdover

networking/advanced_networking/ptp/configuring-ptp.adoc

@@ -69,6 +69,12 @@ include::modules/ptp-configuring-linuxptp-services-as-boundary-clock-dual-nic.ad
 
 include::modules/ptp-configuring-linuxptp-services-as-ha-bc-for-dual-nic.adoc[leveloffset=+2]
 
+//Boundary clocks on Intel Granite Rapids-D hardware
+include::modules/nw-ptp-granite-rapids-boundary-clock-overview.adoc[leveloffset=+2]
+
+// Configuring linuxptp services as a boundary clock on Intel Granite Rapids-D hardware
+include::modules/ptp-configuring-linuxptp-services-as-boundary-clock-gnrd.adoc[leveloffset=+2]
+
 include::modules/nw-ptp-configuring-linuxptp-services-as-ordinary-clock.adoc[leveloffset=+1]
 
 [role="_additional-resources"]