Final answer:
The protocol data unit (PDU) at the Network Layer of the OSI model is called packets.
Step-by-step explanation:
In the Network Layer of the OSI model, the protocol data unit (PDU) is called packets. The Network Layer is responsible for data routing, packet forwarding, and addressing across multiple networks. It ensures the data is transmitted from the source to the destination network.
The PDU associated with different layers of the OSI model has specific names. For example, at the Data Link Layer, the PDU is known as frames, while at the Transport Layer it's referred to as segments (or datagrams in some protocols). In contrast, in the Network Layer, the segmented data from the Transport Layer is encapsulated into packets so it can be routed through various network paths towards its destination.