Various Components Of Computer Network Structure Information Technology Essay

What are the various components of Computer Network structure. Explain in brief.

Write down the differences between connection oriented and connectionless services.

Explain in brief the topologies that are used for broadcasting type of communication.

Television channels are 6MHz wide. How many bits/sec. can be sent if four levels digital signals are used? Assume a noiseless channel.

Which of the OSI layer handles each of the following:

Breaking the transmitted bit stream into frames.

Determining which route through the subnet to use.

Providing compatibility in data and text.

Providing terminal compatibility.

Providing facility for remote login.

Sketch the Manchester and Differential Manchester encoding for the following bit stream: 0111000111001101

For differential Manchester encoding assume the line is initially in the low state.

UPTU 2007-08

Attempt any two parts of the following: (10×2=20)

What do you mean by a computer network? Explain in detail various goals and applications in real life of computer networks.

Give different categorization of the computer networks. What are internetworks? How you will categorize internetworks using above categories of computer networks.

Give a detail description of the functionality of different layer of OSI model.

UPTU 2008-09

Attempt any two parts of the following: (10×2=20)

(i) What do you mean by network topology? Explain in brief any three such network topologies.

(ii) What is difference between TCP/IP and OSI model?

What are channel types in ISDN to construct the transmission structure of any access link? Explain them.

Which types of transmission media are used at physical layer transmission? Give a comparative study of different transmission media in guided media. When unguided media is suitable for transmission?

UPTU 2009-10

Attempt any two parts of the following: (10×2=20)

What are the reasons for using layered protocol? A system has an n-layer protocol Hierarchy. Applications generate messages of length M bytes. At each of the layers, an h-byte header is added. What fraction of the network bandwidth is filled with headers?

(i) If a binary signal is sent over a 3-kHz channel whose signal-to-noise ratio is 20 dB, what is the maximum achievable data rate?

(ii) What is the percent overhead on a T1 carrier; that is, what percent of the 1.544 Mbps are not delivered to the end user?

Explain the advantages and disadvantages if any of the following topologies:

(i) star

(ii) ring

(iii) bus

(iv) mesh

UNIT II

UPTU 2006-07

Attempt any four parts of the following: (5×4=20)

Suppose that the string 0101 is used as the bit string to indicate the end of a frame and the bit stuffing rule is to insert a 0 after each appearance of 010 in the original data; thus 010101 would be modified by stuffing to 01001001. In addition, if the frame proper ends in 01, 0 would be stuffed after the first 0 in the actual terminating string 0101.

Show how the following would be modified by this rule?

11011010010101011101

Measurements of an infinite user slotted ALOHA channel show that 10% of the slots are idle:

(i) What is the channel load, G?

(ii) What is throughput?

(iii) Is the channel underloaded or overloaded?

Consider an error free 64-Kbps satellite channel used to send 512 byte data frames in one direction, with very short acknowledgement coming back the other way. What is the maximum throughput for window sizes of 01 and 07?

A bit stream 10011101 is transmitted used the standard CRC method. The generator polynomial is x3 + 1. Show the actual bit string transmitted. Suppose the third bit from the left is inverted during transmission. Show that this error is detected at the receiver’s end.

Explain Basic-Bit-Map (a collision free protocol) used at MAC sublayer.

Sixteen stations, numbered 1 through 16, are contending for the use a shared channel by using the adaptive Free Walk Protocol. If all the station whose addresses are prime number suddenly becomes ready at once, how many bit slots are needed to resolve the contention?

UPTU 2007-08

Attempt any two parts of the following: (10×2=20)

What is Hamming code? For the following word pattern (message) find out the number of check bit and the bit at eleventh position. If any error is detected, show it.

M = 1111 1010 0000 1110

What are medium access control (MAC) protocols? Discuss salient feature of CSMA/CD protocol.

Describe the bit stuffing rule used the HDLC protocol.

Consider a CSMA/CD network running at 200 Mbps over a 1 Km cable with no repeaters. The signal speed is 2 * 108 m/sec. Compute the minimum frame size.

UPTU 2008-09

Attempt any two parts of the following: (10×2=20)

What do you mean by ALOHA? How does slotted ALOHA improve efficiency?

SEC(7,4) hamming code can be converted into a double error detecting and single error correcting code (8,4) by using an extra parity check. Construct the generator matrix for the code and show that the code is quasi perfect. Design a decoder for the code.

Explain the IEEE 802.3 MAC sublayer frame format. What is the binary exponential back off algorithm?

UPTU 2009-10

Attempt any two parts of the following: (10×2=20)

A large population of ALOHA users manage to generate 50 requests/sec, including both originals and retransmissions. Time is slotted in units of 40 msec.

What is the chance of success on the first attempt?

What is the probability of exactly k collisions and then a success?

Explain the working of CSMA/CD protocol. Why there is a minimum frame length restriction in CSMA/CD?

Explain the working of GO-BACK N ARQ protocol. How it is different from selective repeat ARQ?

UNIT III

UPTU 2006-07

Attempt any two parts of the following: (10×2=20)

Write and explain the kinds of shortest path routing Algorithm in brief.

Find the shortest path in the following subnet using Dijsktra Algorithm, when the source is fixed but destination is not fixed.

Describe the choke-packet method of congestion control. You are also required to explain the variation in the above mentioned algorithm.

Explain the concept of Tunnelling in Internetworking. Write down the difference in IPv4 and IPv6.

UPTU 2007-08

Attempt any two parts of the following: (10×2=20)

Answer the following question:

How is IPv6 different from IP protocol?

Convert IP address whose hexadecimal representation is C22F1582 to dotted decimal notation.

A class B class network on the internet has a subnet mask of 255.255.240.0. What is the maximum number of hosts per subnet?

Explain the purpose of subnetting.

What is Link Control Protocol? Give the format of LCP packet. Also how authentication is supported in PPP? Explain.

(i) A computer on a 6-Mbps network is regulated by a token bucket. The token bucket is filled at a rate of 1 Mbps. It is initially filled to a capacity with 8 megabit. How long can the computer transmit at the full 6 Mbps?

(ii) Discuss the token passing technique used in FDDI.

UPTU 2008-09

Attempt any two parts of the following: (10×2=20)

What is the congestion in network layer? Differentiate and explain Leaky-Bucket algorithm and Token Bucket algorithm?

What is the role of routing algorithm? Explain the working of Distance Vector Routing algorithm with the help of a suitable example.

(i) Explain various phases through which a PPP connection goes using transition state diagram.

(ii) What is the significance of IP address classification? What problems of IPv4 are being addressed by IPv6?

UPTU 2009-10

Attempt any two parts of the following: (10×2=20)

A computer on a 6-Mbps network is regulated by a token bucket. The token bucket is filled at a rate of 1 Mbps. It is initially filled to capacity with 8 megabits. How long can the computer transmit at the full 6 Mbps?

Give a classification of IP addresses used in the Internet. Suppose that instead of using 16 bits for the network part of a class B address originally, 20 bits had been used. How many class B networks would there have been?

(i) The protocol field used in the IPv4 header is not present in the fived IPv6 header. Write your justification.

(ii) IPv6 uses 16-byte addresses. If a block of 1 million addresses is allocated every picosecond, how long will the addresses last?

UNIT IV

UPTU 2006-07

Attempt any two parts of the following: (10×2=20)

Describe Transmission Control Protocol’s (TCP) Transmission policy.

Explain the Remote Procedure Call with suitable diagram. You are also required to explain the use of RPC in Transport layer.

Imagine that a two-way handshake rather than a three-way handshake were used to set up connections. Are deadlocks now possible? Give an example or how what none exist.

UPTU 2007-08

Attempt any two parts of the following: (10×2=20)

Why does UDP exist? Would it not have been enough to just let user processes send raw IP packets?

What are two army problem and a three way handshake? State the elements of transport protocol.

Describe the feature of the following devices:

Routers

Bridges

Gateway

UPTU 2008-09

Attempt any two parts of the following: (10×2=20)

A TCP connection is using a window size of 1000 B and the previous acknowledgement no was 22,001. It receives a segment with acknowledgement no 24,001. Draw a diagram to show the situation of the window after and before the acknowledgement is received. If the window size is change to 11000B and 9000B separately, than what will be the situation?

Discuss the issue to be considered in designing different layers.

(i) What is user datagram protocol? Give its datagram format.

(ii) Would it not have been enough to just let user processes send raw IP packets? Give reason in support to your answer.

UPTU 2009-10

Attempt any two parts of the following: (10×2=20)

Draw the TCP header format and explain its various fields.

A TCP machine is sending full windows of 65,535 bytes over a 1-Gbps channel that has a 10-msec one way delay. What is the maximum throughput achievable? What is the line capacity?

Explain Connection Management at the transport layer in detail.

UNIT V

UPTU 2006-07

Attempt any two parts of the following: (10×2=20)

Explain the architecture of Electronic Mail (i.e. E-mail).

Describe the concept of Domain name System in brief.

Explain the working of server side in the architectural overview of ‘World-Wide-Web (WWW).

UPTU 2007-08

Attempt any two parts of the following: (10×2=20)

One secret key encryption method involves the permutation of bits. For example an 8 bit plain text is permuted, bit 8 becomes bit 3, bit 1 becomes bit 2 and so on. Draw a diagram to show the mapping of each bit to its new designation. Scramble the bits as you please. What is encryption and decryption algorithm?

What do you mean by following :

HTTP

SNMP

How MPEG file format is different from JPEG file format? Encode the following message using Huffman coding:

“INDIAN INNING”

Write short note on one of the following :

Network security and cryptography

Electronic mail and FTP.

UPTU 2008-09

Attempt any two parts of the following: (10×2=20)

One secret key encryption method involves the XOR operation. A bit patter (plaintext) of a fixed size in XORed with a block of bits of the same size to create to fixed sized cipher text. What is the encryption algorithm here? What is the decryption algorithm here? Remember that an XOR algorithm is a reversible algorithm.

(i) Why do we need Domain name space when we can directly use an IP address?

(ii) What is trivial file transfer protocol? How it is different from simple FTP?

(i) What is the role of digital signature in cryptography?

(ii) What is JPEG standard? How it is different from JPEG 2000?

UPTU 2009-10

Attempt any four parts of the following: (5×4=20)

Can a query message in DNS have one question section but the corresponding response message have several answer sections?

Describe the addressing system used by SMTP.

Describe the functions of the two FTP connection. What is anonymous FTP?

Compare the way SMTP and HTTP transfer images. Which one do you think is more efficient? Why?

The Diffie-Hellman key exchange is being used to establish a secret key between Alice and Bob. Alice sends Bob (719, 3, 191). Bob responds with (543). Alice’s secret number, x, is 16. What is the secret key?

Can IPsec using AH be used in transport mode if one of the machines is behind a NAT box? Explain your answer.