Classical

Computer Networks - Data Communication & Network Security

66:  

 Which of the following decides the role (sender or receiver) of a device on a network ?

A.

Line connection

B.

Link connection

C.

Line discipline

D.

Link decision

 
 

Option: C

Explanation :

Line discipline co-ordinate the link system. It determines which device can send and when it can send. Line discipline decides the role of a device on a network. 


67:  

 For stop-and-wait flow control, for n data packets sent, how many acknowledgments are needed ?

A.

n

B.

n-1

C.

2n

D.

n + 1

 
 

Option: A

Explanation :

For stop-and-wait flow control for n data packets sent, in acknowledgements are needed.


68:  

The collision domain of tranditional Ethernet and Fast Ethernet respectively are

A.

250m, 250m

B.

250m, 2500m

C.

2500m, 250m

D.

2500m, 2500m

 
 

Option: C

Explanation :


69:  

In a crossbar with 1000 crosspoints, how many statistically are in use at any time ?

A.

100

B.

250

C.

500

D.

1000

 
 

Option: B

Explanation :

A crossbar switch connects n inputs to m outputs in a grid, using electronic micro switches at each cross point, totally n x m cross points are required for crossbar switch. In general 25 percent of the cross points are used at a given time. The rest are idle so, totally 1000 cross points, so 25% = 250 crosspoint points are in use.


70:  

Which of the following is a time - division switch?

A.

TSI

B.

TDM bus

C.

crosspoint

D.

both (a) and (b)

 
 

Option: D

Explanation :

In time division switch, slots are divided by time switching accomplished using time division multiplexing (TDM) and another device called time slot interchange (TSI).




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