Q35
Single choice
During an authorized security assessment at a municipal power distribution facility in Omaha, Nebraska, a certified ethical hacker performs passive traffic analysis between the control center and several remote substations.
The tester observes structured request-response messages used to read coil status and write register values on industrial controllers. All communication occurs over TCP port 502, and the protocol does not provide built-in encryption or authentication.
Based on these characteristics, which OT communication protocol is operating within this environment?