Cluster V3 SecurityUser. compatibilityMode - In Compatibility mode the Cluster NE-to-NE Communication allow communication with authentication and privacy, but with fixed passwords. The compatibility mode shall be used when not all NEs in a cluster running a release supporting the Cluster NE-to-NE Communication in the secure mode. This ensures communication while upgrade (or downgrade) scenarios. If all NEs in a cluster supporting the secure mode then the secure mode should be used. secureMode - The secure mode uses authentication and privacy with configurable passwords only. Secure mode is the recommended mode during normal operation. Switching to secure mode while not all network elements are upgraded to a release supporting Cluster NE-to-NE Communication security, or while passwords are not set on all network elements leads to communication interruptions.