Final answer:
CSU/DSU and Router are the devices used to make WAN connections.
Step-by-step explanation:
The device used to make WAN connections is the CSU/DSU (Channel Service Unit/Data Service Unit) and Router. These devices play a crucial role in connecting and transmitting data across wide area networks.
The CSU/DSU converts digital data received from the LAN (Local Area Network) into a format suitable for transmission over a WAN (Wide Area Network).
The Router is responsible for directing network traffic between different networks, including WANs. It examines the destination address of each data packet and determines the most efficient path for it to reach its destination.