Cisco® CCNA Exam Cram Notes : WAN Terms

V. WAN Technologies

1. WAN Terms

1. WAN Terms : WANS are connected over serial lines that operate at lower speeds than LANs. Some of the 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. It is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation point.

5. Demarc: Demarcation point between carrier equipment and CPE.

Typical WAN interfaces, that one come across frequently are:

EIA 232, EIA 449, EIA 530, V.35, and X.21. The Cisco router serial interface will be a 60-pin D-shell connector. This in turn is connected to service provider equipment, usually through a CSU/ DSU. Therefore, appropriate conversion cable need to be used when interfacing with a WAN device such a CSU/DSU. CSU/ DSU in turn is connected to the service provider through the cable supplied by the service provider.

Previous    Contents    Next

CCNA Cram Notes Contents
certexams ad

simulationexams ad