How does a model-driven telemetry dial-out approach function?

With dial-out telemetry, the subscription is configured directly on the network device, specifying the collector address, port, encoding, and data paths. The device establishes an outbound connection (typically gRPC) to the collector and streams data at the configured interval, so the collector only needs to listen passively for incoming connections.

This describes the dial-in (on-change or periodic pull) model, where the collector initiates the session to the device and subscribes to the data it wants streamed.

This also describes a dial-in approach where the collector initiates the connection to retrieve previously defined data, the opposite of dial-out behavior.

In dial-out mode the device initiates the session, but the subscription is pre-configured statically on the device - it is not negotiated dynamically with the collector after connection establishment.