Computer Networks Answers

draw a sequence diagram for the below-given scenario :

Completing the counselling process of a student in which the initial message from the system’s user interface is sent to the Counselling object to verify the student. Then the second message to the counsellor objects to prepare a schedule. The counsellor checks for a free slot for counselling and once it is available it will be added to the schedule. Once the schedule is updated a message will be sent to the student object and another message to the user interface to confirm the student schedule.  

Ex [08 Marks]

A Network administrator has been given a range of Class C IP address 192.168.1.0 /24. He has to design a network considering the requirement given below. Each department will get one subnet. Write down all the subnets.                   

Admin: 10 users, Operations: 18 users, Supply Chain: 3 users, IT: 14 users, HR: 5 users,

Branch Office1: 35 users, Branch Office2: 15 users

Ex

a)    How a damaged or lost frame is recovered in a communication between a sender and a receiver using Selective Repeat ARQ. Explain with the help of flow diagram.                        

b)    Bandwidth of the line is 2 Mbps, and 1 bit takes 30 ms to make a round trip. What is the efficiency of the link if a frame size is 1500 bits? Use Go Back-N protocol. Sender is allowed to send 15 frames at a time.

An avalanche effect is also desirable for the key: A one-bit change in a key should result in a dramatically different ciphertext if the plaintext is unchanged. 1. Assume an encryption with a given key. Now assume the key bit at position 1 (prior to PC − 1) is being flipped. Which S-boxes in which rounds are affected by the bit flip during DES encryption? 2. Which S-boxes in which DES rounds are affected by this bit flip during DES decryption?

Describe the important networking applications used by businesses and individuals for communications, information retrieval, and other applications.? List any 2 application.

Note: Read NETWORKING APPLICATIONS in chapter #7 page 259-265.

Definition, Advantages and Disadvantages of Observation, Interview and and Survey

A CSMA/CD protocol is a good choice for a MAC protocol if you want the protocol to provide guaranteed bandwidth allocations to each user.

True

False

Consider congestion control in TCP. When a timeout occur at a sender during slowstart, the value of assthresh is set to one of the previous ssthresh value.

True

False

 IT205

Identify and explain with practical examples the top ten Internet security flaws that system administrators must eliminate to avoid becoming an easy target for hackers.

Strengths and weakness of case study, ethnography, ground theory, narrative inquiry and phenomenology