Which statement best describes the primary function of a CSU/DSU in a leased-line connection?

Which statement best describes the primary function of a CSU/DSU in a leased-line connection?

• A. Acts as a wireless access point
• B. Connects a T-carrier line to customer equipment and performs line encoding/conditioning
• C. Provides DNS services for the LAN
• D. Serves as a network switch

Answer: (B)

In leased-line networks, the CSU/DSU’s job is to terminate the provider’s digital line at the customer site and prep it for the customer’s equipment. It sits between the carrier’s T-carrier circuit (like a T1) and your router or LAN device, providing the necessary line encoding and conditioning so the signal from the carrier is clean and usable by your equipment. It also supplies clocking to the customer side so the DTE device and the line stay in sync, and it can offer basic line monitoring and testing. This is why the function described—connecting a T-carrier line to customer equipment and performing line encoding/conditioning—best captures what a CSU/DSU does. It isn’t about wireless access, DNS services, or switching, which are outside its role.

In leased-line networks, the CSU/DSU’s job is to terminate the provider’s digital line at the customer site and prep it for the customer’s equipment. It sits between the carrier’s T-carrier circuit (like a T1) and your router or LAN device, providing the necessary line encoding and conditioning so the signal from the carrier is clean and usable by your equipment. It also supplies clocking to the customer side so the DTE device and the line stay in sync, and it can offer basic line monitoring and testing. This is why the function described—connecting a T-carrier line to customer equipment and performing line encoding/conditioning—best captures what a CSU/DSU does. It isn’t about wireless access, DNS services, or switching, which are outside its role.