In which layer of the OSI model does the router primarily operate?

The router primarily operates at the Network layer of the OSI model. This layer is responsible for routing data packets between devices across different networks. Routers use logical addressing, such as IP addresses, to determine the best path for data to travel from the source to the destination.

In the context of the OSI model, the Network layer not only facilitates communication between devices on different networks but also handles packet forwarding and routing. This includes managing traffic control, packet sequencing, and error handling that are essential for effective data transmission.

While routers may interact with the lower layers, such as the Data Link, which deals with the physical transmission of packets over a specific medium, their primary function is rooted in making decisions based on network addressing and routing protocols, which are key at the Network layer.