Chapter 16 BB

Question 1

WAN protocols and technologies will all at least occupy which layers of the OSI model? Pg 577

Answer 1

The physical layer, data link (and sometimes network)

Question 2

What is Customer Premises Equipment (CPE)? Pg 577

Answer 2

Equipment owned by the service provider that is located on the subscriber’s property.

Question 3

What is Channel Service Unit (CSU) / Data Service Unit (DSU) ? Pg 577-578

Answer 3

A layer 1 device that connects the serial ports on your router to the provider’s network and connects directly to the demarcation point. Can be internal or external.

CSU/DSU provides clocking of the line to the CPE, also provides voltage regulation.

Question 4

What is a Smart Jack / Network Interface Unit (NIU) ? Pg 578

Answer 4

Installed between the demarc and the CSU/DSU. Provides signal conversion and can regenerate the signal to account for signal degradation. Also provides diagnostic capabilities to the ISP.

Question 5

What is Demarcation Point? Pg 578

Answer 5

The precise spot where the service provider’s or local exchange carrier’s responsibility ends and the CPE begins.

Question 6

What is a Copper Line Driver / Repeaters? Pg 578

Answer 6

Allows for a demarc extension length of up to 5,000 feet from the telephone company’s demarc.

Question 7

What is a Local Loop? Pg 579

Answer 7

Connects the demarc to the closest switching office, known as the central office.

Question 8

What is a Central Office? Pg 579

Answer 8

A phone company building that connects the customer’s network to the provider’s switching network. Also known as a point of pressure (POP).

Question 9

What is a Toll Network? Pg 579

Answer 9

A trunk line inside a WAN provider’s network. This network is a collection of switches and facilities owned by the ISP.