PDUs

PDUs, or Protocol Data Units, may refer to two broad concepts in information technology: electrical power distribution units and the networking notion of protocol data units.

Power distribution unit: A power distribution unit is a device that distributes electrical power to multiple devices within a rack or cabinet. PDUs provide controlled power, protection, and often remote management. Common types include basic, metered, switched, and intelligent PDUs. A basic PDU splits power without measurement; metered PDUs monitor current draw; switched PDUs enable remote outlet control; intelligent PDUs add network connectivity and environmental sensing. Features often include remote monitoring, outlet-level control, alarms, and sensors for temperature, humidity, and airflow. PDUs are widely used in data centers, server rooms, and telecom facilities to improve reliability, capacity planning, energy efficiency, and load management. Some models support redundant power feeds and integration with data-center infrastructure management systems.

Protocol data unit: In networking and telecommunications, a PDU denotes a unit of data exchanged between protocol layers or within a protocol layer. The term helps describe how data is organized and processed as it moves through a stack. Examples include a frame at the data link layer, a packet at the network layer, a segment at the transport layer, and a message or data unit at the application layer. PDUs carry both control information (such as addressing, sequencing, and error detection) and payload, and their structure varies by protocol and layer.

In summary, PDUs can refer to physical hardware for power distribution or to the standard data units defined by networking protocols, depending on the context.