capter 16

Question 1

what is Customer premises equipment (CPE)?

577

Answer 1

Customer premises equipment (CPE) is service provider equipment that is located on the customer’s premises (physical location) rather than on the provider’s premises

Question 2

what is channel service unit / Data service unit ( CSU/DSU)

577

Answer 2

A layer 1 device that performs both the channel service unit (CSU) and data service unit (DSU) functions. it connects the serial ports on the customer’s router to the provider’s network

Question 3

smart jack/ NIU

578

Answer 3

it is installed between the demarcation and the CSU/DSU, it convert codes and protocols into something the customer’s equipment required.

Question 4

central office ( CO )
579

Answer 4

is a phone company that connect the customer network to the provider’s switching network.

Question 5

3 types of WAN connection, what are they?

580

Answer 5

• dedicated lines ( leased)
• Circuit switching
• Packet switching

Question 6

dedicated lines ( leased)

580

Answer 6

it is a point to point, it uses synchronous serial lines up to 45Mbps, uses high level data link Control ( HLDC ) and Point to point protocol ( PPP )

Question 7

Circuit switching

581

Answer 7

low cost, uses dial-up modems or ISDN, it is used for low-bandwidth data transfers.

Question 8

Packet switching

581

Answer 8

this method allows the user to share bandwidth with other users to save money, but it is very slow.

Question 9

what is the slowest WAN connection?

581

Answer 9

dial-up connection is the slowest.

Question 10

what is the sped of modern dial-up modems?

581

Answer 10

the theoretical speed is 56Kbps.

Question 11

what is Synchronous transmission?

Answer 11

Synchronous transmission is a process where data is transferred in regular intervals that are timed by a clocking signal; allowing for a constant and reliable transmission for time-sensitive data, such as real-time video or voice.

Question 12

what is asynchronous?

Answer 12

asynchronous is a data transmission where the communication can start and stop at any time. Data sent through an asynchronous transmission contains a start bit and stop bit, helping the receiving end know when it has received all of its data.

Question 13

what are T series connections?

582

Answer 13

they are digital connection that we can lease from the telephone company, we use them for leased lines that provide synchronous connection between sites.

Question 14

T1 is the basic of the T series connections, it serves 24 digital signal 0 ( DS0). what is the maximum speed of T1?
582

Answer 14

1.544 Mbps

Question 15

what is synchronous optical network ( SONET)

585

Answer 15

is the standard of synchronous data on optical fiber

Question 16

what is the European version of the T1?

583

Answer 16

it is E1, and it operates at 2.048 and uses 32 channels of 64Kbps. uses DS1

Question 17

what is the Japanese version of T1?

583

Answer 17

it is J1, it operates at 1.544Mbps

Question 18

The T3 connection:

584

Answer 18

it is a 44.736Mbps = 28T1 and 672DS0 channels.

uses DS2

Question 19

Wavelength Division Multiplexing, WDM :

585

Answer 19

Wavelength Division Multiplexing, WDM is a technology that multiplexes several carriers on a single optical fiber by using different wavelengths.

Question 20

what is PON ?

586

Answer 20

A passive optical network (PON) is a new option for network connecting home and business to the internet, it uses point-to-multipoint fiber to the end-points in which unpowered optical splitters are used to enable a single optical fiber to serve multiple end-points.

Question 21

what is the downlink and the uplink speed of the PON?

586

Answer 21

downlink is from 155Mbps to 655Mbps.

the uplink speed is 155Mbps

Question 22

what are some of the wireless types?

586

Answer 22

Bluetooth.
Microwave radio relay.
A communication satellite.

Question 23

Microwave radio relay transmit digital and sometime analog signals. T/F
787

Answer 23

True

Question 24

DSL:

588

Answer 24

Digital Subscriber Line, DSL is a method of having high-speed access to the Internet over standard copper lines.
the digital information is sent over a high bandwidth channel above the baseband voice channel on a single pair of wires.

Question 25

Cable modems:

588

Answer 25

this broudband service sends Ethernet digital signals over a cable modem.