VMware Telco Cloud Automation deployments have PTP time synchronization for both the Radio Unit (RU) and Distributed Unit (DU). When there is a loss of time synchronization, the DU application disables transmission until the time synchronization is re-acquired.
PTP Notification APIs are implemented as per the O-RAN.WG6.O-Cloud Notification API-v03.00 Specification. The PTP notification events are as follows:
Synchronization State
PTP Clock Class Change
PTP Lock state Change
GNSS Synchronization State
OS Clock Sync State
The PTP notifications are managed by exposing the REST API to vDU applications to register for PTP synchronization events. The PTP notification framework monitors the PTP status and delivers PTP event notifications to the vDU application.
The following diagram illustrates the components that are required to manage the PTP notifications:
TCA Timing Pod
Timing pod contains Timing Controller, Monitor, and MessageQueue containers.
PTP status is monitored using a monitor container.
Monitor Container pushes the notifications to the DU application through MessageQueue and Sidecar.
Timing pod must be instantiated using CSAR
Sidecar Container
Updated DU specification to run the Sidecar.
DU application communicates with the Sidecar using the localhost address and port, which are exposed to the DU application by k8 Downward API. PTP event notifications are sent to the DU application through REST APIs exposed by Sidecar.
DU application retrieves the current status of PTP as required.
CSAR is provided by VMware.
