# Recent questions tagged computer-networks

1
Start and stop bits are used in serial communication for error detection error correction synchronization slowing down the communication
2
Repeaters function in Physical layer Data link layer Network layer Both (A) and (B)
3
What are the primary characteristics that distinguish a cell from a packet? cells are generally smaller that packets cells do not incorporate physical address all cells have the same fixed length packet cannot be switched
4
In networking terminology UTP means Unshielded Twisted pair Ubiquitious Teflon port Uniformly Terminating port Unshielded T- connector port
5
How many bits are required to encode all twenty six letters, ten symbols, and ten numerals? $5$ $6$ $7$ $46$
6
Bit stuffing refers to Inserting a $’0’$ in user data stream to differentiate it with a flag Inserting a $’0’$ in flag stream to avoid ambiguity Appending a nibble to the flag sequence Appending a nibble to the user data stream
7
The address of a class $B$ Host is to be split into subnets with a $3$-bit subnet number. What is the maximum number of subnets and maximum number of hosts in each subnet? $8$ subnets and $262142$ hosts $6$ subnets and $262142$ hosts $6$ subnets and $1022$ hosts $8$ subnets and $1024$ hosts
8
The maximum data rate of a channel of $3000$-Hz bandwidth and SNR of $30$ db is $60000$ $15000$ $30000$ $3000$
9
Which of the following is minimum error code? Octal Code Binary Code Gray Code Excess-$3$ Code
10
If the original size of data is $40$ then after adding error detection redundancy bit the size of data length is $26$ $36$ $46$ $56$
11
Which of the following would not be specified in a communication protocol? Header contents Trailer contents Error Checking Data content of message
12
Bit stuffing refers to Inserting a $’0’$ in user data stream to differentiate it with a flag Inserting a $’0’$ in flag stream to avoid ambiguity Appending a nibble to the flag sequence Appending a nibble to the user data stream
13
If the channel is band limited to $6\;kHz$ and signal to noise ratio is $16,$ what would be the capacity of channel? $16.15$ kbps $23.24$ kbps $40.12$ kbps $24.74$ kbps
14
Correct expression tor UDP user datagram length is length of UDP = length of IP- length of IP header's length of UDP= length of UDP-length of UDP header's length of UDP = length of IP+length of IP header's length of UDP = length of UDP+length of UDP header's
15
Closed - Loop control mechanism try to : Remove congestion after it occurs Remove congestion after sometime Prevent congestion before it occurs Prevent congestion before sending packets
16
In classless addressing, there are no classes but addresses are still granted in : Codes Blocks IPs Sizes
17
Which multiple access technique is used by $\text{IEEE } 802.11$ standard for wireless $\text{LAN}$ ? $\text{CDMA}$ $\text{CSMA/CA}$ $\text{ALOHA}$ None of the options
18
$PGP$ encrypts data by using a block cipher called : international data encryption algorithm private data encryption algorithm internet data encryption algorithm none of the options
19
A subnet mask in class $C$ can have _____________ $1$’s with the remaining bits $0$’s. $10$ $24$ $12$ $7$
20
What is the value of acknowledgement field in a segment Number of previous bytes to receive Total number of bytes to receive Number of next bytes to receive Sequence of zero's and one's
21
Which of the following is a class $B$ host address ? $230.0.0.0$ $130.4.5.6$ $230.7.6.5$ $30.4.5.6$
1 vote
22
There is a need to create a network that has $5$ subnets, each with at least $16$ hosts. Which one is used as classful subnet mask ? $255.255.255.192$ $255.255.255.248$ $255.255.255.240$ $255.255.255.224$
1 vote
23
Which NetWare protocol provides link - state routing ? $NLSP$ $RIP$ $SAP$ $NCP$
24
Which layer connects the network support layers and user support layers ? transport layer network layer data link layer session layer
1 vote
25
When we use slow-start algorithm, the size of the congestion window increases _______ until it reaches a threshold. Additively Multiplicatively Exponentially None of the options
26
In $IPv4$ Addresses, classfull addressing is replaced with : Classless Addressing Classfull Addressing Subnet Advertising None of the options
1 vote
27
An Ethernet destination address $07-01-12-03-04-05$ is : Unicast address Multicast address Broadcast address All of the options
1 vote
The demerits of the fragmentation are : Complex routers Open to DOS attack No overlapping of fragments $\left (A \right)$ and $\left ( B \right)$ both