This read-create CmProtSwitchDirection object specifies the supported protection switch direction for the group, and does not apply when cmFacProtGroupSwitchMode is dualactiverx. It defines whether the protection switch acts on one traffic direction only or both directions together across the facility pair. For example, a unidirectional setting means only the affected direction of traffic switches to protect while the return path stays on working, which matters when diagnosing an asymmetric outage report.