ArubaOS-CX real-time notifications subsystem

The ArubaOS-CX real-time notifications subsystem enables external clients to connect to the switch through WebSocket secure and subscribe to receive real-time notifications about the switch resources and the configuration changes, state changes, and statistical information that interest them.

The Aruba OS-CX REST API, combined with the built-in databases that provide configuration, state, statistical data, and time-series data for the features and protocols running in the switch, provide a powerful means for switch programmability.

When a REST API is used for monitoring devices, it inherently implements the polling initiated from the client side. However, polling does not address the specific use cases in which network management systems need to receive live data or real-time events from the switch. There is a need to have a live notification subsystem that provides the remote network management system with real-time information about any changes that occur in the switch. Timely information about changes is important for troubleshooting and statistical data analyses, as well as for the immediate reaction to real-time events.

The ArubaOS-CX operating system provides built-in database that stores all configurations, states, and all statistical data for features and protocols running in the switch. When the switch image is built, a proprietary algorithm generates REST APIs and corresponding documentation for all resources in the database. Each resource or collection of the resources inside the switch is uniquely identified by its URI. The ArubaOS-CX real-time notification subsystem provides the ability for remote clients get real-time monitoring capability provided by the REST API by subscribing to the switch resource identified by its unique URI.

The WebSocket protocol is the considered to be the best protocol in the industry to use for real-time notifications. The WebSocket protocol was selected based on latency, throughput, resource utilization, network overhead, and security requirements. The handshake part of the WebSocket protocol uses HTTPS, so there is no need to open a new port on the switch side, and there is no need to provide a new authentication mechanism. Multiple clients and connections are supported.

ArubaOS-CX notification messages have JSON encoding, which was designed to align with REST payloads to allow clients to use combined REST and notification solutions.

The ability to subscribe to these push notifications about a variety of types of information about the switch, combined with the structured nature of the JSON data reported by the switch database, enable a form of network monitoring commonly called telemetry streaming.

Interested clients, known as subscribers, might include the following:

  • Web clients such as the ArubaOS-CX Web UI

  • Network management systems

  • Monitoring scripts