ESAT Forouzan - Chapter 8: Circuit Switching and Telephone Networks

Question 1

The _____ is a device that connects n inputs to m outputs.
a. Crosspoint
b. Crossbar
c. Modem
d. RAM

Answer 1

b. Crossbar

Question 2

How many crosspoints are needed in a single-stage switch with 40 inputs and 40 outputs?
a. 40
b. 50
c. 90
d. 2000

Answer 2

d. 2000

Question 3

In a crossbar with 1000 crosspoints, approximately how many are in use at any time?
a. 100
b. 250
c. 500
d. 1000

Answer 3

b. 250

Question 4

The _____ of a TSI controls the order of delivery of slot values that are stored in RAM.
a. Crossbar
b. Crosspoint
c. Control unit
d. Transceiver

Answer 4

c. Control unit

Question 5

In _____ circuit switching, delivery of data is delayed because data must be stored and retrieved from RAM.
a. Space-division
b. Time-Division
c. Virtual
d. Packet

Answer 5

b. Time-Division

Question 6

To create a _____, combine crossbar switches in stages.
a. Multistage switch
b. Crosspoint
c. Packet Switch
d. TSI

Answer 6

a. Multistage switch

Question 7

Which of the following is a time-division switch?
a. TSI
b. TDM bus
c. Crosspoint
d. (a) and (b)

Answer 7

d. (a) and (b)

Question 8

In a time-division switch a _____ governs the destination of a packet stored in RAM.
a. TDM Bus
b. Crosspoint
c. Crossbar
d. Control Unit

Answer 8

d. Control Unit

Question 9

A telephone network is an example of _____ network.
a. Message Switch
b. Packet Switched
c. Circuit Switched
d. None of the above

Answer 9

c. Circuit Switched

Question 10

The local loop has _____ cable that connects the subscriber telephone to the nearest end office.
a. Twisted-Pair
b. Coaxial
c. Fiber-Optic
d. (b) and (c)

Answer 10

a. Twisted-Pair

Question 11

Trunks are transmission media such as _____ the handle the telephone communication between offices.
a. Twisted-pair cable
b. Fiber-optic cable
c. Satellite links
d. (b) and (c)

Answer 11

d. (b) and (c)

Question 12

The established telephone company that provided services in a LATA before 1966 and owns the cabling system is called _____.
a. An ILEC
b. A CLEC
c. An IXC
d. A POP

Answer 12

a. An ILEC

Question 13

A new telephone company that provides services in a LATA after 1966 is called _____.
a. An ILEC
b. A CLEC
c. An IXC
d. A POP

Answer 13

b. A CLEC

Question 14

The telephone service handled between two LATAs is called _____.
a. An ILEC
b. A CLEC
c. An IXC
d. A POP

Answer 14

c. An IXC

Question 15

If the end office receives two bursts of analog signals with frequencies of 697 and 1477 Hz, then the number _____ has been punched.
a. 1
b. 2
c. 3
d. 4

Answer 15

c. 3

Question 16

Data from a computer are _____: the local loop handles _____ signals.
a. Analog; analog
b. Analog; digital
c. Digital; digital
d. Digital; analog

Answer 16

d. Digital; analog

Question 17

A traditional telephone line has bandwidth of _____.
a. 2000 Hz
b. 4000 Hz
c. 2000 MHz
d. 4000 Mhz

Answer 17

b. 4000 Hz