Step 3. Understanding how to interface with a RESTCONF API
There are multiple ways to interface with a RESTCONF API. Some controllers such as Cisco's Open SDN Controller (OSC) expose a northbound RESTCONF interface. Consuming RESTCONF as a northbound interface (NBI) in this fashion enables the user to configure multiple devices or gather operational data across the network from a centralized controller. In doing so, the controller uses the required southbound interface (such as NETCONF, OpenFlow, or BGP-LS) to operate the network infrastructure accordingly.
Also, individual network devices are exposing RESTCONF interfaces directly. Through projects such as OpenConfig, engineers are modeling common configuration scenarios using the YANG data modeling language. When a device supports an OpenConfig YANG model, this ensures a consistent API across devices regardless of the network operating system or vendor. This allows network engineers and software engineers alike to write applications or scripts against a consistent RESTCONF API. Note that in the example shown below, the Orchestrator may be a product from a vendor, a simple Python script, or a complex, custom application.
In the next part of the exercise, we shall make our first RESTCONF API call using Postman to Cisco's Open SDN Controller!