Q18. Which of the following is a term associated with WAN terminology / is a WAN device? [Select all that apply].

A. Demarc

B.  DSU/CSU

C. Modem

D. CPE

Correct answer: A, B, C, D

Explanation:

WANs are connected over serial lines that operate at lower speeds than LANs. Some important  WAN terms are:
1. Modems: Modems connect to public telephone circuits through dial-up.
2. CSU/DSU: Stands for Channel Service Unit / Data Service Unit. CSU/DSUs are used for connecting to Central Office of a Telephone switching company and provides serial WAN connections.
3. Multiplexors (mux): Multiplexors combine two or more signals before transmitting on a single channel. Multiplexing can be done by sharing "time" or "frequency".
4. CPE stands for Customer Premise Equipment.
5. Demarc : Demarcation point between carrier equipment and CPE.