181. What signal-to-noise ratio is needed to put a T1 carrier on a T0-kHz line ?

63 db

73 db

83 db

93 db

182. If data rate of ring is 20 Mbps, signal propagation speed is 200 b/ms, then number of bits that can be placed on the channel of 200 km is

2000 bits

20,000 bits

1,000 bits

none of these

183. A field in the Ethernet message packet is

Type

data

address

none of these

184. Minimum number of bits required to represent all the symbols together is

15

14

12

11

185. Which of the following measures the number of lost or garbled messages as a fraction of the total sent in the sampling period ?

Residual error rate

Transfer failure probability

Connection release failure probability

Connection establishment failure probability

186. Maximum data rate of a channel for a noiseless 3-kHz binary channel is

3000 bps

1500 bps

6000 bps

none of these

187. Number of cross point needed for 10 lines in a cross point switch which is full duplex in nature and there are no self-connection is

100

45

8

. 28

188. The systems that can be used in both priority and non-priority modes is

TDM

Register insertion

Carrier sense systems

all of these

189. In the carrier sense network, if prevailing condition is a 'channel busy', then technique used is

non-persistent then it results in randomised wait and sense

1-persistent then the channel is continually sensed

p-persistent then randomised retransmission is done

both (a) and (b)

190. Start and stop bits are used in serial communication for

error detection

error correction

synchronization

slowing down the communication

191. Slotted ALOHA

divide time into discrete intervals

require global time synchronization

both (a) and (b)

none of these

192. Working of the WAH generally involves

telephone lines

micro waves

satellites

All of these

193. Which of the following program is used to copy files to or from another using time sharing system over a single link ?

VMTP

TFTP

UUCP

UART

194. A station in a network forward incoming packets by placing them on its shortest output queue. What routing algorithm is being used ?

Hot potato routing

Floding

Static routing

Delta routing

195. Four bits are used for packed sequence numbering in a sliding window protocol used in a computer network. What is the maximum window size ?

4

8

15

16

196. Which of the following digits are known as the terminal number of the network user address

5-7

1-4

8-12

13-14

197. Which of the following digits are known as the area code of the network user address (NUA) ?

5-7

1-4

8-12

13-14

198. How many digits of the DNICC (Data Network Identiication Code) identify the country ?

First three

First four

First five

First six

199. How many digits of the network user Address are known as the DNIC (Data Network Identiication Code) ?

First three

First four

First five

First seven

200. Establishing a virtual connection is virtually equivalent to

connecting as virtual memory

physically connecting a DTE and DCE

placing a telephone call prior to a conversion

placing a modem prior to a conversion