Two Components of a WAN Connection

AB.

A WAN (Wide Area Network) connection is used to connect devices over a wide geographical area, often between different cities or countries. Two essential components of a WAN connection are:

1. CSU/DSU: CSU/DSU stands for Channel Service Unit/Data Service Unit. It is a hardware device that connects a terminal or data device to a digital circuit, such as a T1 or T3 line. The CSU/DSU acts as an interface between the digital circuit and the customer's equipment. The CSU/DSU is responsible for converting the digital signal from the customer's equipment into a format that can be transmitted over the digital circuit, and vice versa. The CSU/DSU is also responsible for ensuring that the quality of the signal meets the required standards.

2. Router: A router is a device that connects two or more networks together and forwards data packets between them. In the context of a WAN connection, a router is used to connect a LAN (Local Area Network) to the WAN. The router is responsible for receiving data packets from the LAN, encapsulating them in a WAN protocol, and forwarding them over the WAN. The router also receives data packets from the WAN, decapsulates them, and forwards them to the appropriate device on the LAN.

Therefore, the correct answers to the question are A (CSU/DSU) and B (router). C (bridge), D (hub), and E (switch) are not components of a WAN connection, but rather components of a LAN. A bridge connects two LANs together, a hub is a device that connects multiple devices in a LAN, and a switch is a device that connects multiple devices in a LAN and forwards data packets between them.