How does Cisco NSO communicate with network devices in the southbound direction?

Cisco NSO (Network Services Orchestrator) primarily communicates with network devices in the southbound direction using protocols that facilitate configuration management and operational commands. The correct answer includes NETCONF, CLI (Command-Line Interface), SNMP (Simple Network Management Protocol), and OpenFlow.

NETCONF is a network management protocol that allows for the configuration of network devices in a consistent and programmatic manner. It provides mechanisms to install, manipulate, and delete the configuration of network devices using XML-based data encoding. This aligns well with modern network automation practices where programmability is key.

CLI is a traditional method for directly interfacing with devices, allowing engineers to execute commands directly on devices. Cisco NSO can leverage CLI for devices that may not support more modern protocols but still require automation and orchestration capabilities.

SNMP is a widely used protocol for managing devices on IP networks. It is effective for collecting information from and configuring network devices, making it a staple in network management.

OpenFlow enables network devices to be directly controlled by a controller, allowing for dynamic management of the device's forwarding behaviors. It is more commonly associated with Software-Defined Networking (SDN), but it can play a role in NSO's capabilities as it can be integrated with other protocols for