Network Security Subcategories

Networking Overview I	Network Hardware
Freshers	Socket Secure Layer I
Network Security	Classful Addressing
Experienced	Secure Shell I
Designing Subnets I

Generate the CRC codeword for the data word 1101011011 using generator 10011. Also write both in the polynomial form.

A. 1.10101e+13
B. 1.10101e+13
C. 1.10101e+13
D. 1.10101e+13

Explanation: Solve using polynomial division and then appending the remainder to the divisor.

A slotted ALOHA network transmits 200-bit frames using a shared channel with a 200-kbps bandwidth. Find the throughput if the system (all stations together) produces 1000 frames per second.

A. 92 frames
B. 368 frames
C. 276 frames
D. 151 frames

Explanation: G =1 S=G×e−G=0.368 (36.8%) Throughput = 1000 × 0.0368 = 368 frames.

After performing bit stuffing on the following stream : 01101111111111111110010, the output is-

A. 1.10e+24
B. 1.10e+24
C. 1.00e+25
D. 1.10e+24

Explanation: Bit stuffing involves adding a 0 after every five 1s during transmission.

A device that helps prevent congestion and data collisions –

A. Switch
B. Hub
C. Gateway
D. Proxy server

Explanation: A switch is a device that splits large networks into smaller segments, decreasing the number of users sharing the same network resources and bandwidth.

Assume we need to download text documents at the rate of 100 pages per second. What is the required bit rate of the channel?

A. 1.846 mbps
B. 1.536 mbps
C. 2.4 mbps
D. None of the mentioned

Explanation: Average No, of lines u=in each page = 24 Each line has 80 char. Each char required 8 bits 100 x 24 x 80 x 8 = 1,536,000=1536 Mbps.

Nsub = n + log2(N/Nsub) is used to find the suffix length.

A. True
B. Is use
C.
D.

Explanation: Nsub = n + log2(N/Nsub) is used to find the prefix length.

A packet has arrived in which the offset value is 100, the value of HLEN is 5 and the value of the total length field is 100. What is the number of the last byte

A. 880
B. 879
C. 881
D. 801

Explanation: Total data bytes = total length – header length = 80 bytes in this datagram. Last byte is therefore 879.