This selects whether this APS group provides protection switching in just one direction (unidirectional) or in both directions simultaneously (bidirectional), and notably this object becomes locked once the group's cApsConfigRowStatus is active, meaning the admin must get this decision right during initial provisioning or take the group out of service to change it. Bidirectional protection ensures both the near-end and far-end simultaneously switch to protection together, which matters for keeping a symmetric protected path, while unidirectional only guarantees protection in the direction it's configured for. For example, an admin who provisions a group as unidirectional but later needs bidirectional protection would have to transition cApsConfigRowStatus out of active first before this field becomes modifiable again.