COMPUTER NETWORKS/CS2302

QUESTION BANK

REGULATION 2008

DEPARTMENT OF INFORMATION TECHNOLOGY

UNIT-I - PART –A

1. What are the two types of line configuration? [Nov/Dec 2010]

It is the way two or more communication devices attach to a link.A Link is the physical communication pathway that transfers data from one device to another.Point to PointProvide dedicated link between two devices use actual length of wire or cable to connect the two endincluding microwave & satellite link. Infrared remote control & tv remote control.Multipoint.Also known as Multidrop line configuration one or more than two specific devices share a single linkcapacity of the channel is shared

2.What do you mean by error control? [Nov/Dec 2010]

Error control is the process of detecting and correcting both the bit level and packet level errors.

Types of Errors

Single Bit Error

The term single bit error means that only one bit of the data unit was changed from 1 to 0 and 0 to 1.

Burst Error

In term burst error means that two or more bits in the data unit were changed. Burst error is also called packet level error, where errors like packet loss, duplication, reordering.

3. What is flow control? (NOV/DEC 2011)

Flow control is the process of managing the rate of data transmission between two nodes to prevent a fast sender from outrunning a slow receiver. It provides a mechanism for the receiver to control the transmission speed, so that the receiving node is not overwhelmed with data from transmitting node.

4. Define error detection and error correction. ? (NOV/DEC 2011)

Error detection is the detection of errors caused by noise or other impairments during transmission from the transmitter to the receiver.[1]

Error correction is the detection of errors and reconstruction of the original, error-free data.

5. State the major functions performed by the presentation layer of the ISO OSI model. [Nov/Dec 2006]

The presentation layer establishes context between application-layer entities, in which the higher-layer entities may use different syntax and semantics if the presentation service provides a mapping between them. If a mapping is available, presentation service data units are encapsulated into session protocol data units, and passed down the stack.

This layer provides independence from data representation (e.g., encryption) by translating between application and network formats. The presentation layer transforms data into the form that the application accepts. This layer formats and encrypts data to be sent across a network. It is sometimes called the syntax layer.

The original presentation structure used the Basic Encoding Rules of Abstract Syntax Notation One (ASN.1), with capabilities such as converting an EBCDIC-coded text file to an ASCII-coded file, or serialization of objects and other data structures from and to XML.

6. State the purpose of layering in networks? [May/Jun 2007] (May/June 2013)

A layer is a collection of related functions that provides services to the layer above it and receives services from the layer below it.

To execute the functions by each layer is independent

7.At which level of OSI model does repeaters, bridges, routers and gateways operate? [May/Jun 2007] Repeater works at Physical Layer Bridge works at Data Link Layer Router works at Network Layer Gateway works at All Seven Layers

8.Define the term Protocol and give its key elements. [Nov/Dec2007] (Apr/May 2011)

A protocol can be defined as a set of rules determining the format and transmission of data or a set of rules that governs data communication. A protocol defines what is going to be communicated. The key elements of protocol are 1. Syntax2.Semantics 3.Timing

9.List the issues associated with RS-232 standard. [Nov/Dec2007]

The RS-232 standard has three basic categories of issues related to RS-232. They are, Some engineering specifications are absolutely explicit. Voltage levels Baud rate values Shape of the signals that represent ‘1’s and ‘0’s The specifications for the interface circuitry The purpose for each wire used in the cable There are some general guidelines allowing certain issues to be flexible. The method to start and stop the flow of data The method to coordinate the sender and receiver Some considerations have no specifications in the standard. The way that characters are represented by bits The type of connector used to attach the cable ends

10.Draw a hybrid topology with a star backbone and three ring networks? [Apr/May2008]

11.What is the significance of twisting in twisted pair cable? [Apr/May2008]

They are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs.

12.For n devices in a network, what is the number of cable links required for a mesh, ring, star topology?

[ NOV/DEC 2008].

No of cables required:

1. Mesh Topology: n(n-1)

2. Ring: n

3. Star: n

13. What does the Shannon capacity have to do with communications? [ NOV/DEC 2008].

It has to do with data communication. It is called the Shannon channel capacity theory where double the bandwidth equals double the highest data rate. This is of course theoretically and does not take into account white noise (thermal noise), impulse noise, attenuation distortion or delay distortion.

14.List the layers in the OSI model that handle end-to-end connections.[May/June 2009]

Network Layer Transport layer Session Layer Presentation Layer Application Layer

13. List out the five components of data communication system [Apr/May2010]Data communication has five basic components: the message, the sender, the receiver, the medium and the protocol.

14. Differentiate : Intranet and Internet. [Apr/May2010]An intranet is a private computer network that uses Internet technologies to securely share any part of an organization's information or operational systems with its employees. Sometimes the term refers only to the organization's internal website, but often it is a more extensive part of the organization's computer infrastructure and private websites are an important component and focal point of internal communication and collaboration.

The Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite (TCP/IP). It is a network of networks that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by copper wires, fiber-optic cables, wireless connections, and other technologies

15. What are the two types of line configuration? [NOV/DEC 2010] Point to Point Point to Multipoint

16. What do you mean by error control? [NOV/DEC 2010]Error control refers primarily to methods of error detection and retransmission. Anytime an error is detected in an exchange, specified frames are retransmitted. This process is called automatic repeat request (ARQ).

17. What is Flow control ? (Nov/Dec 2011)It is the regulation of sender’s data rate so that the receiver buffer doesn’t become overwhelmed.i.e. flow control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgement.

18. What is Data Communication? (Apr/May 2011)High speed data exchange between computers and/or other electronic devices via cable or wireless.

19. What is the use of two dimensional parity error detection? (Nov/Dec 2012)

20. What are the issues in data link layer? (Nov/Dec 2012) Framing Physical Addressing Error Control Flow Control Access Control

21. Mention the advantage and disadvantage of error correction by receiver, as compared to error detection?

(May/June 2013)

It is the mechanism to correct the errors and it can be handled in 2 ways. a) When an error is discovered, the receiver can have the sender retransmit the entire data unit. b) A receiver can use an error correcting coder, which automatically corrects certain errors.

22.Consider a data stream consisting of ten 0s. Encode this stream using the following encoding schemes.

Compare the number of transitions that occur in the encoded streams .[May/June 2009]

a) NRZ-

b) Manchester

c) AMI

PART B

1. (i) What is a Protocol? List the three key elements of a protocol. [Nov/Dec 2006]

(ii) With relevant examples differentiate between simplex, half duplex and full duplex communication.

[Nov/Dec 2006]

(iii) A Sine wave completes one cycle in 25 μs. What is its frequency? Express the frequency in KHz.

[Nov/Dec 2006]

(iv) A digital signal has a bit interval of 40 μs. What is the bit rate? Express the bit rate in Kbps.

[Nov/Dec 2006]

2. (i) An analog signal carries four bits in each signal element. If 1000 signal elements are sent per second, find the

baud rate and the bit rate. [Nov/Dec 2006]

(ii) Discuss the role played by repeaters in Terrestrial Microwave communication? Is the distance between

repeaters fixed? Discuss. [Nov/Dec 2006]

(iii) A network has ‘n’ devices. Determine the number of cable links required for a mesh, ring, bus and star

topology. [Nov/Dec 2006]

3. (i) List four properties by which transmission media can differ. (4) [May/Jun 2007]

(ii) Three packets – switching networks each contain n nodes. The networks has a star topology has a star topology

with a central switch, a ring respectively and a third is fully interconnected with a wire form every node to every

other node. What are the best, average and worst case transmission paths in hops? (12) [May/Jun 2007]

4 (i). Describe the key elements of protocols and the standards. (8) [May/Jun 2007]

(ii). Explain in detail the data transmission in OSI reference model. (8) [May/Jun 2007]

5(i) Explain Layers in OSI model. (8 mark) [Nov\Dec2007]

(ii) Explain the Star and Bus topologies of computer networks. (8 marks) [Nov\Dec2007]

6 (i) Explain about Coaxial cable and Fiber Optics media for communication. (8 marks) [Nov\Dec2007]

(ii) Explain about the transmission modes available for data flow. (4 marks) [Nov\Dec2007]

(iii) Explain the categories of networks. (4 marks) [Nov\Dec2007]

7. What is the difference between a protocol and a service interface? Explain your answer in terms of the

ISO seven layer models. (16 marks) [Apr/May2008]

8. Explain how guided media differ from unguided media? Briefly explain any three methods used for data

ransmission using guided media and two methods used for data transmission using unguided media. (16 marks)

[Apr/May2008]

9. Discuss briefly about the layers present in the OSI model. [MARKS 16] [ NOV/DEC 2008].

10. (i) Discuss briefly about the line coding process used for converting digital data to digital signals.

[MARKS 10] [ NOV/DEC 2008].

(ii) Write a short note on transmission media. [MARKS 6] [ NOV/DEC 2008].

11. (i) Discuss the various line encoding techniques used to send analog and digital data on digital

channels(12) [May/June 2009]

(ii) Calculate the baud rate for the following: (4) [May/June 2009]

(1) 2000 bps FSK; (2)

6000 bps 8-PSK; (3)

6000 bps 16-QAM;

(4) 6000 bps tribit.

12. (i) Explain how full duplex data transmission takes place on a RS232 DTE-DCE interface. [12]

[May/June 2009]

(ii) A modified NRZ code known as enhanced NRZ (E-NRZ) is sometimes used for high density magnetic

tape recording. E-NRZ entails separating the NRZ-L data stream into 7-bit word; inverting bits

2,3,6 and 7; and adding one parity bit to each word to ensure odd parity. What are the advantages of E-NRZ

over NRZ-L? Any disadvantages? [4] [May/June 2009]

13. Explain the various layers present in OSI model and their functions. [Apr/May2010]

14. (i) Discuss the different network topologies in detail with their performance indicators. [Apr/May2010] (ii)

Write a short note on various types of transmission media, highlighting their merits and demerits. [Apr/May2010]

15. Explain in detail the error detection and error corrections. [NOV/DEC 2010]

16. Discuss in detail about the layers of OSI model. [NOV/DEC 2010]

17. Discuss the ISO OSI model (Nov/Dec 2011)

18. Explain different types of multiplexing? (Nov/Dec 2011)

19. Explain in detail OSI/ISO reference model with diagram . (Apr/May 2011)

20. Explain about various transmission media used by data communication media. (Apr/May 2011)

21. Draw the OSI network Architecture and explain the functionalities of every layer in detail.(16)(Nov/Dec 2012)

22 .Explain the following error Detection Mechanism (16) (Nov/Dec 2012)

a) CRC b ) Discuss Briefly about Link Level Flow Control

23. Discuss the framing techn ique used in HDLC. What is the effect of errors on this framing? (8)(May/June 2013)

24. The message 11001001 is to be transmitted , using CRC error detection algorithm. Assuming the CRC polynomial to be x3 +1, determine the message that should be transmitted, If the second left most bit is corrupted , show that it is dertected by the receiver. (8) (May/June 2013)

25. Discuss the principal of stop and wait flow control algorithm. Draw time line diagrams and explain how loss of a frame and loss of an ACK are handled. What is the effect of delay - bandwidth product on link utilization? (May/June 2013)

26. Assume that a frame consistes of 6 characters encoded in 7-bit ASCII. Attach a parity bit for every character to maintain even parity. Also attach a similar parity bit for each bit position across each of the bytes in the frame. Show that such a 2-dimensional parity scheme can detect all 1-bit ,2-bit and 3-bit errors and can correct a single bit errors. (May/June 2013)

24. Name the four basic network Topologies and explain them giving all the relevant features. (Nov/Dec 2010)

UNIT-II - PART –A

1. Briefly discuss stop-and-wait method of flow control. [Nov/Dec 2006]

Stop-and-wait ARQ is a method used in telecommunications to send information between two connected devices. It ensures that information is not lost due to dropped packets and that packets are received in the correct order. It is the simplest kind of automatic repeat-request (ARQ) method.

2. List the two types of data frames in FDDI. [Nov/Dec 2006]

Fiber Distributed Data Interface has two types of data frames.They are Asynchronous and Synchronous data frames.

3. State the difference between token ring and FDDI? [May/Jun 2007]

Token ring uses single ring, FDDI uses additional ring to achieve better results and less chance of failure. Token ring uses twisted pair cables and FDDI uses fiber cables.

FDDI uses a timed token protocol where Token Ring uses priority/reservation token access, leading to difference in frame format and how station traffic handled.

Token ring uses priority and reservation bits, but the priority operation of the FDDI ring uses a principle that is based on a parameter known as the Token Rotation Time.

4. Give the structure of encoder and decoder in error correction. [May/Jun 2007]

5. What is Modulo-2 arithmetic? [Nov\Dec2007]

Modulo-2 arithmetic is an arithmetic system where every result is taken modulo-2. Here are some examples:

6. Define the term SONET? [Nov\Dec2007]

Short for Synchronous Optical Network, a standard for connecting fiber-optictransmission systems. SONET was proposed by Bellcore in the middle 1980s and is now an ANSI standard.SONET defines interface standards at the physical layer of the OSI seven-layer model.

7. What is the main purpose of the second ring in the FDDI protocol? [Apr/May2008]

FDDI consists of a primary ring for data transmission and a secondary ring that assist in failure situations

8. Assume a Go-Back-N protocol is used with a window size of 4 and that the ACK for packet 2 gets lost.

Show the events until packet 2 is acknowledged at the sender side. [Apr/May2008]

9. How does a single-bit error differ from a burst error? [ NOV/DEC 2008].

The term single bit error suggest that only one bit in the given data unit sush as byte is in error.this means that only one bit will change from 1 to 0 or 0 to 1..In case of burst error,if two or more bits from a data unit such as bte change from 1 to 0 or from 0 to 1 then burst errors are said to have occured.the lenghth of burst is measured from the first corrupted bit to last corrupted bit.

10. Compare a piconet and a scatter net. [ NOV/DEC 2008].

A piconet is the type of connection that is formed between two or more Bluetooth-enabled devices such as modern cell phones or PDAs. A scatternet is a number of interconnected piconets that supports communication between more than 8 devices. Scatternets can be formed when a member of one piconet (either the master or one of the slaves) elects to participate as a slave in a second, separate piconet.

11. Assuming a framing protocol that uses bit stuffing, show the bit sequence transmitted over a link when

the frame contains the bit sequence 1111011111101001111101011111110. Mark the stuffed bits. [May/June

2009]

12. What is the size of the smallest Ethernet frame? What determines this size? .[May/June 2009]

The minimum payload is 42 octets when 802.1Q tag is present and 46 octets when absent.[2][note 4] and the maximum payload is 1500 octets.

13. What are the responsibilities of data link layer in internet model? [Apr/May2010]

The data link layer is responsible fora. framing data bitsb. providing the physical addresses of the sender/receiverc. data rate controld. detection and correction of damaged and lost frames

14. Which ARQ mechanism utilizes pipelining? [Apr/May2010]

Go back N Selective ARQ mechanism uses pipelining.

15. What are the functions of Bridges? [NOV/DEC 2010]

Device used to connect two separate Ethernet networks into one extended Ethernet. Bridges only forward packets between networks that are destined for the other network. Term used by Novell to denote a computer that accepts packets at the network layer and forward them to another network.”

16. What is the advantage of FDDI over a basic Token Ring? [NOV/DEC 2010]

Although they both use a rotating ring setup, the FDDI uses two to achieve better results and less chance of failure. FDDI also uses a timed protocol that leads to differences in frame format and how station traffic is controlled.

17. What is CSMA/CD? (Nov/Dec 2011)

Short for Carrier Sense Multiple Access / Collision Detection, a set of rules determining how network devices respond when two devices attempt to use adata channel simultaneously (called a collision).

The CSMA/CD method is internationally standardized in IEEE 802.3 and ISO 8802.3.

18. What is meant by bridge? (Nov/Dec 2011) A bridge device filters data traffic at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments.Bridges operate at the data link layer (Layer 2) of the OSI model.

19. An IP packet has arrived with an M bit value of 1 and fragmentation offset value is 0. what do you infer

from this? (Apr/May 2011)

20. Differentiate fast Ethernet and gigabit Ethernet? (Nov/Dec 2012)

Gigabit Ethernet Network is an upgrade on Fast Ethernet Network equivalent to Fast Ethernet Networks improvement over Fast Ethernet Network, offering speeds of 1000 Megabits (1 Gigabit) .

21. What is the difference between switch and bridge? (Nov/Dec 2012)

Bridge can connect only TWO networks/ LANs/ Hosts, means bridge has only TWO ports. While...

Switch can connect more than TWO networks/ LANs/ Hosts because switch has more than TWO ports.

Or you can say that a bridge with more than TWO ports is known as a Switch.

22. How is the minimum size of an ethernet frame determined? (May/June 2013)

The minimum frame size of an Ethernet packet is determined by how long it takes for a collision to occur. It has to be large enough so that if a collision occurs it will be detected before the transmission is completed.

23. How does an FDDI node determine whether it can send asynchronous traffic and synchronous traffic?

(May/June 2013)

PART-B1. (i) A block of 32 bits has to be transmitted. Discuss how the thirty two bit block is transmitted to the

receiver using Longitudinal Redundancy Check. [Nov/Dec 2006]

(ii) Consider a 32 bit block of data 11100111 11011101 00111001 10101001 that has to be transmitted. If

Longitudinal Redundancy Check is used what is the transmitted bit stream? [Nov/Dec 2006]

(iii) In the Hamming code, for a data unit of m bits how do you compute the number of redundant bits ‘r’

needed? [Nov/Dec 2006]

(iv) What kinds of errors can Vertical Redundancy check determine? What kinds of errors it cannot

determine? [Nov/Dec 2006]

2. (i) List the three main functions performed by the data link layer of the ISO OSI model. [Nov/Dec 2006]

(ii) Explain the working of Carrier Sense Multiple Access protocol. [Nov/Dec 2006]

(iii) How does a Token Ring LAN operate? Discuss. [Nov/Dec 2006]

(iv) List and briefly discuss the two different basic transmission technologies that can be used to set up

wireless LAN’s. [Nov/Dec 2006]

3. (i) How does the 802.11 media access control protocol ensure that the receiver has a greater chance to

transmit the acknowledgement frame before any other wireless stations grab the media? Does it always

guarantee that the acknowledgement frame sent by the receiver will not collide with another frame transmitted

by another wireless station? (8) [May/Jun 2007]

(ii) Describe the collision avoidance mechanism used in 802.11 wireless LAN. In particular, how such a

mechanism solves the hidden terminal problem. (8) [May/Jun 2007]

4. Describe two approaches by which packet loss is detected in a Go back –N ARQ protocol and Selective

Repeat. [May/Jun 2007]

5. (i) Explain CRC error detection mechanism with an example. (8 marks) [Nov\Dec2007]

(ii) Explain HDLC in detail. (8 marks) [Nov\Dec2007]

6. (i) Explain the frame format of IEEE 802.3 and IEEE 802.5 in detail. (10 marks) [Nov\Dec2007]

(ii) What is CSMA/CD? Explain. (6 marks) [Nov\Dec2007]

7. Go-back-n and selective-reject are two basic approaches to deal with transmission errors. [Apr/May2008]

(i) Compare the two approaches in terms of storage and bandwidth requirements. (8 marks)(ii) With the aid of a packet sequence (timing) diagram, show the operation of go-back-n when a

data packet/ACK-packet/NAK-packet is corrupted. (8 marks) 8. Station A has two frames in a queue ready to send at the same time. On an 802.3 CSMA/CD network, is it

guaranteed that Station B’s frame will be transmitted before the second frame of Station A is transmitted? Why?

What is the answer for the same scenario on an 802.5 token ring network? Assume all frames have the same

priority. (16 marks) [Apr/May2008]

9. (i) With an example, illustrate how CRC encoder and decoder will work. [MARKS 10] [ NOV/DEC2008].

(ii) Compare and contrast the Go-Back-N ARQ protocol with selective repeat ARQ. [MARKS 6] [

NOV/DEC 2008].

10.(i) Discuss in detail about the wireless LAN MAC sub layers. [MARKS 8] [ NOV/DEC 2008].

(ii) Discuss briefly about the high speed networks. [MARKS 8] [ NOV/DEC 2008].

11. (i) Explain the techniques used in the 802.11 protocol for wireless networks.[12] [May/June 2009]

(ii) Draw the sender and receiver windows for a system using go-back-n ARQ for the following scenario (n = 4) : [May/June 2009]

Frame 0 is sent; frame o is acknowledged.

Frames 1 & 2 are sent; and acknowledged.

Frames 3 & 4 are sent; NAK 4 is received.

Frames 4,5 & 6 are sent ; and all are acknowledged. [4]

12. (i) Explain the operation of the FDDI protocol. Highlight the differences with respect to the 802.5 token ring

protocol. [12] [May/June 2009]

(ii) Let A and B be two stations attempting to transmit frames on an Ethernet network. A collision occurs.

[May/June 2009]

1.What is the probability that A gets to transmit its First frame A1 immediately after the first

collision?

2.After that transmission A tries to send frame A2 and B its First frame B1. Will a collision occur? What

is the probability of the collision?

3.If a collision occurs, and a back-off takes place, what is the probability that A wins the race again?

13.(i) Discuss the sliding window protocol in detail. [Apr/May2010]

(ii) Explain two problems in 802.11 MAC sub layer protocol. [Apr/May2010]

14. (i) Write a short note on SONET. [Apr/May2010](ii) Discuss any two error correction techniques used in wireless links. [Apr/May2010]

15. Name the four basic network topologies and explain them giving all the relevant features. [NOV/DEC2010]

16. Explain the functioning of wireless LAN in detail. [NOV/DEC 2010]

17. Discuss the ISO OSI model (16)(Nov/Dec 2011)

18. Explain different types of multiplexing?(16) (Nov/Dec 2011)

19. Differentiate between logical address and physical address? (Apr/May 2011)

20. What is burst error? (Apr/May 2011)

21. Explain the Physical Properties of Ethernet 802.3 with necessary diagram of Ethernet Transceiver and

Adapter (16) (Nov/Dec 2012)

22. How does a bridge come to learn on which port the various hosts reside? Explain with example(8)

(Nov/Dec 2012)

23. Write Briefly about CSMA (8) (Nov/Dec 2012)

24. An IEEE 802.5 token ring has 5 stations and a total wire length of 230 m. How many bits of delay must the

monitor insert into the ring? Calculate this for both 4 Mbps and 16 Mbps rings. The propagation speed may be

assumed to be 2.3 *10 8

m/s. (6) (May/June 2013)

25. Discuss the problems encountered in applying CSMA/CD algorithm to wireless LANs. How does

802.11 specification solve these problems.(10) (May/June 2013)

26. Discuss the limitations of bridges. (6) (May/June 2013)

27. Determine the maximum distance between any pair of stations in a CSMA/CD network with a data rate of 10

Mbps, for the correct operation of collision detection process, assuming the minimum frame size to be

512 bits. What should be the maximum distance if the data rate is increased to 1 Gbps? 2 stations A and B ,

connected to the opposite ends of a 10-Mbps CSMA/CD network, start transmission of long frames at times t1=90

and t2=3 µ s respectively. Determine the instants when A hears the collision and B hears the collision. Signal

propagation speed may be assumed as 2*10 8

m/s. (May/June 2013)

UNIT-III - PART –A

1. List the two forms in which virtual circuit packet switching is implemented. [Nov/Dec 2006]

FDDI supports real-time allocation of network bandwidth, making it ideal for a variety of different application types. FDDI provides this support by defining two types of traffic: synchronous and asynchronous. Synchronous traffic can consume a portion of the 100-Mbps total bandwidth of an FDDI network, while asynchronous traffic can consume the rest. Synchronous bandwidth is allocated to those stations requiring continuous transmission capability. Such capability is useful for transmitting voice and video information, for example. Other stations use the remaining bandwidth asynchronously. The FDDI SMT specification defines a distributed bidding scheme to allocate FDDI bandwidth.

2. Which class does the following IP address belong to? [Nov/Dec 2006]

3. What is meant by IP spoofing? How can be router be used to prevent IP spoofing? [May/Jun 2007]

A technique used to gain unauthorized access to computers, whereby the intruder sends messages to a computer with an IP address indicating that the message is coming from a trusted host. To engage in IP spoofing, a hacker must first use a variety of techniques to find an IP address of a trusted host and then modify the packet headers so that it appears that the packets are coming from that host.Newer routers and firewall arrangements can offer protection against IP spoofing.

4. What kind of routing information do routers exchange among themselves while running distance vector

algorithm? In particular, briefly describe the format of the routing information that is exchanged. [May/Jun

2007]

In distance vector algorithm, the routers exchange their routing table with other neighbor routers.The routing table consist information’s on Network ID, Cost and Next Hop for the neighbors.

5. Give an account on Private addresses. [Nov\Dec2007]

An IP address is considered private if the IP number falls within one of the IP address ranges reserved for private uses by Internet standards groups. These private IP address ranges exist:

10.0.0.0 through 10.255.255.255169.254.0.0 through 169.254.255.255 (APIPA only)172.16.0.0 through 172.31.255.255192.168.0.0 through 192.168.255.255

6. What is the meaning of multiple IP address of Router? [Nov\Dec2007]

7. Is 3.54.81.76 a class A, B, C or D IP address? What are the network ID and host ID in decimal notation?

Assume that subnets are not used. [Apr/May2008]

8. What are the two main reasons that hierarchical routing is employed in the Internet, rather than using

a single link-state or distance vector protocol to route packet globally? [Apr/May2008]

Hierarchical routing is a method of routing in networks that is based on hierarchical addressing. Most Transmission Control Protocol/Internet Protocol (TCP/IP) routing is based on a two-level hierarchical routing in which an IP address is divided into a network portion and a host portion. Gateways use only the network portion until an IP datagram reaches a gateway that can deliver it directly. Additional levels of hierarchical routing are introduced by the addition of subnetworks.

9. What are the differences between classful addressing and classless addressing in IPV4? [ NOV/DEC

2008].

The default class addresses are Class A 0-127, Class B - 128-191 Class C - 192-223 for the 1st octet values

Classful ip addresses are ip addresses that follow this standard subnet ranges for class A, B, C so a classful router protocol like ripv1 will always assume that the address 172.16.1.2 has a subnet mask of 255.255.0.0 even if you want it to have a subnet of 255.255.255.0 so on a classful router protocol 172.16.1.2 will always have the range 172.16.0.0 - 172.16.255.255 (because the value 172 in the 1st octet falls in the Class B range of 128-191 and class B addresses have the subnet mask set to 255.255.0.0)

Classless ip addresses mean that the address range is determined by the subnet mask and hence the same address 172.16.1.2 255.255.255.0 will now be looked at as having its range as 172.16.1.0 - 255 because 255.255.255.0 corresponds to that range.

10. Is the size of the ARP packet fixed? Explain. [ NOV/DEC 2008].

No, The ARP packet size must vary because it contains 2 Hardware/MAC addresses in it and 2 different protocol addresses in it. Depending on the datalink and network protocol used the size addresses vary

11. Identify the class/ speciality of the following IP addresses: .[May/June 2009]

a)

110.34.56.45 b)

127.1.1.1

c) 212.208.63.23

d) 255.255.255.255

12. What is the purpose of the Address Resolution Protocol (ARP)? .[May/June 2009]

ARP is used to mediate between ethernet (or other broadcast link-level protocols) and the network layer, or IP protocols. Put more simply, ARP converts IP addresses to ethernet addresses.

13. State the duties of network layer. [Apr/May2010]

Source to destination delivery of packets. Logical addressing of packets. Routing the packets through intermediate nodes to the destination.

14. Define geographic routing. [Apr/May2010]

Geographic routing (also called georouting or position-based routing) is a routing principle that relies on geographic position information. It is mainly proposed for wireless networks and based on the idea that the source sends a message to the geographic location of the destination instead of using the network address.

15. What is DHCP? (Nov/Dec 2012)

The Dynamic Host Configuration Protocol (DHCP) is a network protocol used to configure devices that are connected to a network so they can communicate on that network using the Internet Protocol (IP). The protocol is implemented in a client-server model, in which DHCP clients request configuration data, such as an IP address, a default route, and one or more DNS server addresses from a DHCP server.

16. What are the salient features of IPV6? (Nov/Dec 2012)

The following are the features of the IPv6 protocol: New header format Large address space Efficient and hierarchical addressing and routing infrastructure Stateless and stateful address configuration Built-in security Better support for quality of service (QoS) New protocol for neighboring node interaction Extensibility

17. Compare circuit switching and virtual circuit based packet switching. in respect of queing and forwarding delays. (May/June 2013)

Virtual circuit switching means the packet switching behaves like circuit switching. Connections between devices are completed by using dedicated nodes or routes for packet transmission. Each packet includes a connection identifier and delivered in an order.

Circuit switching is the most commonly use in for the dedicated telecommunication field. But this is strong concept the developer use for communication that provide reliability and consistent connection that established between one node to another node. So, many people have strong misunderstanding about circuit switching that only use in establishment of voice analog and voice circuit but in fact the circuit switching is provide more than consistency connection among the network.

18. Differentiate between connection less operation and connection oriented operation. (May/June 2013)

connection less operation connection orientedConnectionless means that no effort is made to set up a dedicated end-to-end connection.

IP, UDP , ICMP, DNS, TFTP and SNMP are

examples of connectionless protocols in use on

the Internet.

Connection-Oriented means that when devices communicate, they perform handshaking to set up an end-to-end connection.

TCP is an connection oriented protocol.

19. Define subnetting. (Nov/Dec 2011)

A subnetwork, or subnet, is a logically visible subdivision of an IP network.[1] The practice of dividing a network into two or more networks is called subnetting.

20. What is meant by circuit switching? (Nov/Dec 2010)

Circuit switching is a methodology of implementing a telecommunications network in which two network nodes establish a dedicated communications channel (circuit) through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the duration of the communication session. The circuit functions as if the nodes were physically connected as with an electrical circuit.

The defining example of a circuit-switched network is the early analog telephone network.

21. What is multicasting? (Nov/Dec 2010) (Nov/Dec 2011)

In computer networking, multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source. Copies are automatically created in other network elements, such as routers, but only when the topology of the network requires it.

22. What is the function of a router? (Nov/Dec 2010)

The router is the piece of hardware used to connect computers and other devices to each other wirelessly. In most cases, a router is used to grab the signal from the modem, and shoot it out across the house or local area for your computer to grab and use!

PART – B

1.(i) State which layers of the ISO OSI model does the following interconnecting devices operate. [Nov/Dec

2006]

(ii) State the major difference between Distance Vector Routing and Link State Routing. Discuss how these

routing techniques work. [Nov/Dec 2006]

2. (i) What is subnetting? Discuss. Also state which classes of IP address can be subnetted. [Nov/Dec 2006]

(ii) What is subnet masking? Discuss. [Nov/Dec 2006]

(iii) How can we prove that we have 2, 147, 48, 648 address in class A? [Nov/Dec 2006]

(iv) What is the subnetwork address if the destination address is 200.45.34.56 and the subnet mask is

255.255.240.0? [Nov/Dec 2006]

3. (i). How is the looping problem solved by switches and by routers? How do switches and by routers. How

do switches/routers handle link failure? (8) [May/Jun 2007]

(ii). Explain the IP addressing. (8) [May/Jun 2007]

4. (i). Compare and Contrast Link State and Distance Vector algorithms. (8) [May/Jun 2007]

(ii). In the virtual circuit network service model, before a virtual circuit is setup, the source router needs to specify a

path (e.g., the shortest path) from the source to the destination. What additional information do we need to

maintain in the routing table to support this function? Write down the resulting routing table. (8) [May/Jun 2007]

5. (i) Explain about Special IP addresses in detail. (8 marks) [Nov\Dec2007](ii) A company is granted the

site address 201.70.64.0. The company needs 6 subnets. Design the subnets. (8 marks) [Nov\Dec2007]

6. (i) Explain Link state routing. (8 marks) [Nov\Dec2007]

(ii) Explain Routing table and Routing module. (8 marks) [Nov\Dec2007]

7. Given the network topology below, use a link-state algorithm to compute the shortest path from A to all other

nodes. Make sure to show the results of the computation at each step. (16 marks) [Apr/May2008]

7B

D

12

1

1

10

A C E13

8. (i) How do subnetting and supernetting enhance scalability? What is the purpose of a subnet mask and a

supernet (CIDR) mask? Is a subnet mask visible outside an IP network? Is a CIDR mask visible outside an IP

network? [Apr/May2008]

(ii) What are the network number, subnet number, and host number for address 135.104.192.100, mask

255.255.128.0 ? [Apr/May2008]

(iii) How many addresses are spanned by the CIDR address 205.12.192.0/20, and what range do they span?

[Apr/May2008]

9. Discuss in detail about the OSPF routing protocol. [MARKS 16] [ NOV/DEC 2008].

10. (i) Discuss briefly about the network address translation. [MARKS 10] [ NOV/DEC 2008].

(ii) Define fragmentation and explain why the IPV4 and IPV6 protocol need to fragment some packets.

[MARKS 6] [ NOV/DEC 2008].

11. (i) Discuss the various switching techniques used in networks. [12] [May/June 2009]

(ii) Consider sending a 2000-byte datagram that has arrived at a router R1 that needs to be sent over a link that has

an (maximum transmission unit) MTU size of 500 bytes to R2. Then it has to traverse a link with an MTU of 200

bytes. Let the identification number of the original datagram be 351. How many fragments are generated? What

are the parameters associated with these fragments? [4] [May/June 2009]

12 (i) Explain the working of distance vector routing protocol with an example. [12] [May/June 2009]

(ii) For the routing table shown below, what does the router do with packets addressed to the following

addresses? [4] [May/June 2009]

1) 128.96.180.192

Subnet Number

128.96.170.0

Subnet Mask

255.255.254.0

Nexthop

Interface 0

2) 128.96.167.151 128.96.168.0 255.255.254.0 Interface 1

3) 128.96.169.192 128.96.166.0 255.255.255.0 R2

4) 128.96.165.121

Default

128.96.164.0

R4

255.255.252.0 R3

13. (i) What is the purpose of subnetting? Explain the various subnet mask. [Apr/May2010]

(ii) Briefly explain the various routing techniques in detail. [Apr/May2010]

14. (i) Write a short note on Network Address Translation [Apr/May2010]

(ii) How will you transmit the packets by using Datagram approach? Explain in detail with neat diagram.

[Apr/May2010]

15. Write notes on the following: [NOV/DEC 2010]

(i) Internet Protocol

(ii) Routers.

16. Discuss in detail the various aspects of IPv6. [NOV/DEC 2010]

17. Compare circuit switching with packet switching.(16) (Nov/Dec 2011)

18. Illustrate and explain UDP and its packet format. (16) (Nov/Dec 2011)

19. Describe the flow control protocols for noisy channels.(Apr/May 2011)

20. Explain 802.3 and 802.11 standars? (Apr/May 2011)

21. Explain in detail about ARP (10) (Nov/Dec 2012)

22. What is Subnetting ? Explain (6) (Nov/Dec 2012)

23. Explain the Following(16) (Nov/Dec 2012)

Error Reporting (ICMP)

InterDomain Routing

24. A 4480-byte datagram is to be transmitted through an ethernet with a maximum data size of 1500 bytes in frames. Show the values of total length, M Flag, identification and fragment offset fields in each of the fragments created out of the datagram. (May/June 2013)

25.Discuss the principles of reliable flooding and its davatages and applications. (May/June 2013)

26.For the following network, develop the datagram forwarding table for all the nodes. The links are labeled with relative costs. The tables should forward each packet via the least cost path to destination. (May/June 2013)

27. What is the need for ICMP? Mention any four ICMP messages and their purpose. (May/June 2013)

UNIT-IV - PART –A

1. What is a datagram socket? [Nov/Dec 2006]A datagram socket is a type of connectionless network socket, which is the sending or receiving point for packet

delivery services. Each packet sent or received on a datagram socket is individually addressed and routed. Multiple packets sent from one machine to another may arrive in any order and might not arrive at the receiving computer.

2. “TCP software is implemented as a Finite State Machine”, Discuss. [Nov/Dec 2006]

Like a Finite State Machine, the TCP software follows and tracks all the events happening during connection establishment, connection termination and data transfer.

3. Briefly describe two advantages of using packet switching for data transmission. [May/Jun 2007]a. Packet switching supports data and other non-voice transmissions. Non-voice transmissions have busty

of data which sends at idle of time.b. It supports higher data rate services.c. It is flexible. Each and every data packet has its own route path to reach the destination.

4.Explain how TCP flow control works. [May/Jun 2007]TCP flow control mechanism achieve using Sliding window mechanism that generates that the receive buffer does not overflow. To avoid congestion, TCP uses the Additive Increase and Multiple Decrease (AIMD) concepts.The TCP sender is not allowed to send more data than the receiver can receive. Because TCP connections are full duplex, this happens in both directions.

5. Give the format for UDP datagram and give the meaning for each field. [Nov\Dec2007]

UDP is an end-to-end transport level protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer. The packet produced by the UDP is called a user datagram.

o Source port address – Sender’s port addresso Destination port address – Receiver’s port addresso Total length – Total length of the user datagram in bytes.o Check sum – 16 bit field used in error detection.

6.Define the terms (a) Jitter (b) Socket address. [Nov\Dec2007]

(a) Jitter – It is an unwanted variation of one or more characteristics of a periodic signal in electronics and telecommunications. Jitter may be seen in characteristic such as the interval between successive pulses, or the amplitude, frequency, or phase of successive cycles. Jitter is a significant factor in the design of almost all communications links.

(b) Socket address – Sockets can be named with an address so that processes can connect to them. The socket layer treats an address as an opaque object. Applications supply and receive addresses as tagged, variable-length byte strings. Addresses always reside in a memory buffer on entry to the socket layer. A data structure called a socket address can be used as a template for referring to the identifying tag of each socket address

7.Do port addresses need to be unique? Why of why not? [NOV/DEC 2008]

Port addresses are smaller than IP addresses because their domain is smaller.

Port addresses does not necessarly need to be unique. But port addresses together with the IP address uniquely identifies the particular server program on a particular host.

Port Adresses need to be unique for some well known applications. Ex: NTp Server , TFTP Server,FTP Server etc

8. What are the field on which the UDP checksum is calculated? Why? [May/June 2009]

Checksum is the 16-bit one's complement of the one's complement sum of a pseudo header of information from the IP header, the UDP header, and the data, padded with zero octets at the end (if necessary) to make a multiple of two octets.

In other words, all 16-bit words are summed using one's complement arithmetic. The sum is then one's complemented to yield the value of the UDP checksum field.

If the checksum calculation results in the value zero (all 16 bits 0) it should be sent as the one's complement (all 1s).

The difference between IPv4 and IPv6 is in the data used to compute the checksum.

9. What is the purpose of TCP Push Operation? [Apr/May2010]

The PSH flag in the TCP header informs the receiving host that the data should be pushed up to the receiving

application immediately.

10. What are the advantages of using UDP over TCP? [NOV/DEC 2010]

The following are advantages of using UDP over TCP:

1) UDP does not need the overhead required to detect reliability.

2) It does not need to maintain the unexpected deception of a data flow.

3) UDP requires less processing at the transmitting and receiving of hosts

4) It is simple to use for a network.

5) The operating system does not need to maintain UDP connections information.

11. What is TCP? (Nov/Dec 2011)

The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite (IP), and is so common that the entire suite is often called TCP/IP. TCP provides reliable, ordered, error-checked delivery of a stream of octets between programs running on computers connected to a local area network, intranet or the public Internet. It resides at the transport layer.

12. Define congestion. (Nov/Dec 2011)

Network congestion occurs when a link or node is carrying so much data that its quality of service deteriorates. Typical effects include queueing delay,packet loss or the blocking of new connections. A consequence of these latter two is that incremental increases in offered load lead either only to small increases in network throughput, or to an actual reduction in network throughput.

13.. What is an IntServ? (Apr/May 2011)

IntServ or integrated services is an architecture that specifies the elements to guarantee quality of service (QoS) on networks. IntServ can for example be used to allowvideo and sound to reach the receiver without interruption.

IntServ specifies a fine-grained QoS system, which is often contrasted with DiffServ's coarse-grained control system.

The idea of IntServ is that every router in the system implements IntServ, and every application that requires some kind of guarantees has to make an individual reservation. Flow Specs describe what the reservation is for, while RSVP is the underlying mechanism to signal it across the network.

PART-B

1. (i) List and discuss the various primitives for a simple transport service. [Nov/Dec 2006]

(ii) “DNS can use the services of UDP or TCP using port 53”. Discuss when UDP is used and when TCP is

used. [Nov/Dec 2006]

(iii) Highlight the features of UDP and briefly discuss the same. [Nov/Dec 2006]

2. (i) Discuss connection establishment and connection release in TCP. [Nov/Dec 2006]

(ii) Discuss how TCP provides reliability using error control. [Nov/Dec 2006]

(iii) Discuss the strategies TCP uses to avoid congestion. [Nov/Dec 2006]

3. If UDP does not provide any service guarantees or reliable transfer, why can’t application directly access

IP and do without it? Explain UDP in details. (16) [May/Jun 2007]

4. What is QoS in internetworking? State the technique to improve QoS. (16) [May/Jun 2007].

5. (i) Explain the Steps involved in computing Checksum for an UDP Datagram. (12 marks) [Nov\Dec2007]

(ii) Explain Four-way Handshaking method to terminate a connection in TCP? (4 marks) [Nov\Dec2007]

6 (i) Explain about TCP Congestion control technique in detail. (8 marks) [Nov\Dec2007]

(ii) What is Silly Window Syndrome? How do you avoid it? (8 marks) [Nov\Dec2007]

7. Compare and contrast the two TCP/IP transport protocols: TCP and UDP, in terms of demultiplexing,

reliability, and flow control. How does TCP identify a connection? Is the information needed for this identification

readily available to the TCP software in the received TCP segment? Explain. With the help of a diagram, explain

how a connection is established in TCP. (16 marks) [Apr/May2008]

8. How many RTTs does it take until the sender’s congestion window reaches 1Mbytes? Recall that the

congestion window is initialized to the size of a single segment, and assume that the slow-start threshold is

initialized to a value higher than the receiver’s advertised window. If the time to send the file is given by the

number of required RTTs times the RTT value, what is the effective throughput for the transfer? What

percentage of the link bandwidth is utilized? (16 marks) [Apr/May2008]

9.How the connection is established using three-way handshaking, explain in detail?

[ NOV/DEC 2008].

10 (i) Discuss briefly about the techniques used to improve QoS. [MARKS 8] [ NOV/DEC2008].

(ii) Discuss about the Intserv, a flow-based QoS model. [MARKS 8] [ NOV/DEC 2008].11.(i) Explain the working of TCP using the state diagram.[12] [May/June 2009]

(ii) Suppose the letters “abcdefgh” are sent 1 per second over a TCP connection with an RTT of 4.5 secs.

Draw a timeline indicating when each packet is sent and what it contains. [4] [May/June 2009]

12. (i) Discuss the operations of IntServ for providing QoS. [12] [May/June 2009]

(ii) Suppose you are downloading a large file over a 3 kbps phone link. Your software displays an average bytes

per second counter. How will TCP congestion control and occasional packet losses cause this counter to

fluctuate? [4] [May/June 2009]

13. (i) What are four general techniques to improve quality of service? Explain [8] [Apr/May2010]

(ii) How is IP address space divided into different classful addresses? Explain [8] [Apr/May2010]

14. (i) Compare and contrast WDM and FDM multiplexing techniques.[8] [Apr/May2010]

(ii) Draw and explain the integrated services architecture for RSVP. [8] [Apr/May2010]

15. With neat architecture, explain TCP in detail. [NOV/DEC 2010]

16. Explain adaptive flow control in detail and its uses. [NOV/DEC 2010]

17. Explain in detail about congestion avoidance algorithm. (Nov/Dec 2011)

18. With the Help of the network Diagram, Explain how TCP messages a Byte Stream. Give an Example. (10)

(Nov/Dec 2012)

19. Explain any one Congestion Control Algorithm(6) (Nov/Dec 2012)

20. What is DDNS? (Apr/May 2011)

21. Briefly explain bucket bricade attack? (Apr/May 2011)

20. Explain the Addictive Increase/ Multiplicative Decrease Methods ueds in TCP for congestion Control(Nov/Dec 2012)

21. Give and explain the TCP header Format (Nov/Dec 2012)

22.Suppose TCP operates over a 1-Gbps link, utilising the full bandwidth contineously. How long will it take

for the sequence numbers to wrap around completely?uppose an added 32-bit timestamp field increments 1000

times during this wrap around time, how long will it take for the timestamp field to wrap around?(8)

(May/June 2013)

23. What is the need for Nagle's algorithm? How does it determine when to transmit data?(8) (May/June 2013)

24. A TCP machine is sending full windows of 65,535 bytes over a 1-Gbps network that has a 10-ms one-

way delay. What is the throughput achievable? What is the efficiency of transmission? How many bits are

needed in the Advertised window field of a proposed reliable byte stream protocol(like TCP) running over the

above network, for achieving maximum efficiency? (May/June 2013)

25. Illustrate the features of TCP that can be used by the sender to insert record boundaries into the byte

stream. Also mention their original purpose. (May/June 2013)

UNIT-V – PART-A

1.What is a Domain Name Server? [Nov/Dec 2006]

A name server is a computer server that hosts a network service for providing responses to queries against a directory service. It maps a human-recognizable identifier to a system-internal, often numeric identification or addressing component. This service is performed by the server in response to a network service protocol request.

2.State the application layer protocol in the TCP/IP protocol suite that provides access to a networked file server. [Nov/Dec 2006]

Application ayer protocols are most often associated with client–server applications, and the commoner servers have specific ports assigned to them by the IANA:HTTP has port 80; Telnet has port 23; etc. Clients, on the other hand, tend to use ephemeral ports, i.e. port numbers assigned at random from a range set aside for the purpose. The application layer Application contains the higher-level protocols used by most applications for network communication. Examples of application layer protocols include the File Transfer Protocol (FTP) and the Simple Mail Transfer Protocol (SMTP)

3.Why is DNS necessary? State it significance. [May/Jun 2007]For unique client/server identification in the network, the DNS is necessary. It

provides two addressing scheme number-based Internet Protocol addresses and test-based Domain Name System (DNS) names. A domain name is a textual address for a location on the Internet.

4.What is Security Parameter Index? [May/Jun 2007]

The Security Parameter Index (SPI) is an identification tag added to the header while using IPsec for tunneling the IP traffic. This tag helps the kernel discern between two traffic streams where different encryption rules and algorithms may be in use.

5.What is MIME? [Nov\Dec2007]

Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of email to support:

Text in character sets other than ASCII

Non-text attachments

Message bodies with multiple parts

Header information in non-ASCII character sets

6. Give an account on Steganography. [Nov\Dec2007]

Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form ofsecurity through obscurity. The word steganography is of Greek origin and means "concealed writing" from the Greek words steganos (στεγανός) meaning "covered or protected", and graphei(γραφή) meaning "writing".

7. Distinguish between iterative and recursive DNS queries? [Apr/May2008]

Iterative: where your client makes a dns query to your primary dns server asking it for the best info it has, without requesting info from other dns servers. For example, you ask for the ip address of google.com, your primary dns server doesn't know, and refers you to another server.

Recursive: where your client makes a dns query to your primary dns server asking for a definitive answer, even if it has to ask other dns servers. For example, you ask for the ip address of google.com, your primary server doesn't know, so it asks another dns server if it has the info. If so, your primary servers returns the answer. If not, the primary servers asks yet another server, and so on, until it can return the answer to you.

8. How is HTTP similar to SMTP? [ NOV/DEC 2008].HTTP is like SMTP because the data transferred between the client and server are similar in appearance to SMTP messages. Also, the format of the messages is controlled by MIME-like headers.

9. What is SMTP? [NOV/DEC 2010] [Nov/Dec 2012]

The TCP/IP protocol supports electronic mail on the Internet is called Simple Mail Transfer (SMTP). It is a system for sending messages to other computer users based on e-mail addresses. SMTP provides mail exchange between users on the same or different computers.

10. What is telnet? (Nov/Dec 2011)

Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. User data is interspersed in-band with Telnet control information in an 8-bit byte oriented data connection over the Transmission Control Protocol (TCP).

11. What is PGP? (Nov/Dec 2010)

Pretty Good Privacy (PGP) is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting and decrypting texts, e-mails, files, directories and whole disk partitions to increase the security of e-mail communications.

12. What is DNS? (Apr/May 2011)

Domain Name System (DNS) is an internet service that translates domain names into IP Address. It is divided into three sections

1. Generic domains

2. Country domains

3. Inverse domains

13. How is HTTP related to WWW? (Apr/May 2011)

HTTP is a protocol used to access data on World Wide Web. HTTP transfers data, hyper text, audio, video etc.

14. What is cipher text?(Apr/May 2011)

The data (plain text) to be transferred through the network is converted to another form called cipher text(conversion is done using an encryption algorithm)

15. List out the two modes of IP Security(Apr/May 2011)

Transport Mode

Tunnel Mode

17. State the purpose of SNMP? (Nov/Dec 2011)

The main purpose of an SNMP(Simple Network Management Protocol) message is to control (set) or monitor (get) parameters on an SNMP agent. In SNMP, a parameter is an instance of a more generic object. For example, an SNMP agent may have several instances of a microphoneMute object -- one instance for each microphone input.

18. Why name Services are some times called as Middleware [Nov/Dec 2012)]

The Data Distribution Service for Real-Time Systems (DDS) is an Object Management Group (OMG) m2m middleware standard that aims to enable scalable, real-time, dependable, high performance and interoperable data exchanges between publishers and subscribers

21. What are the advantages of allowing persistent TCP connections in HTTP? (May/June 2013)

HTTP persistent connection, also called HTTP keep-alive, or HTTP connection reuse, is the idea of using a single TCP connection to send and receive multiple HTTP requests/responses, as opposed to opening a new connection for every single request/response pair.

PART-B

1. (i) With a relevant example discuss how the domain space is divided. [Nov/Dec 2006]

(ii) Distinguish between a fully qualified domain name and a partially qualified domain name.

Give relevant example. [Nov/Dec 2006]

2. (i) Discuss how Simple Mail Transfer Protocol (SMTP) works? Can multimedia messages be

transmitted using SMTP? Discuss. [Nov/Dec 2006]

(ii) Is Common Gateway Interface a language? Discuss. [Nov/Dec 2006]

3. What are the following acronym SMTP, FTP, WWW and HTTP stand for? Explain their uses and

state the strengths and weaknesses of each of them.(16) [May/Jun 2007]

4. (i). Explain in role of a DNS on a computer network, including its involvement in the process of a

user accessing a web page. (8) [May/Jun 2007]

(ii) Describe about symmetric – key Cryptography. (8) [May/Jun 2007]

5. Explain the followings related with FTP: [Nov\Dec2007]

(i) Connections and communications (8 marks) (ii) Commands (8 marks)

6. Explain the followings related with HTTP: [Nov\Dec2007]

(i) Messages (8 marks) (ii) Headers (8 marks)

7. You are going to use a terminal of the host xyz.cse.edu to write an email from your email account to

my email account, with the content “I wanna pass!” Write down in sequence the commands in SMTP,

along with any necessary argument, that you need to use to send this email. (16 marks)

[Apr/May2008]

8. Describe with an example how does a HTTP request retrieves the document usr/users/doc/doc 1.

Use atleast two general headers, two request headers and one entity header. Show the response if the

document has moved to usr/deads/doc 1 and if there is a syntax error in the request. (16 marks)

[Apr/May2008]

9 (i) Discuss briefly about the DNS in the internet. [MARKS 8] [ NOV/DEC 2008].

(ii) Discuss briefly about the file transfer protocol. [MARKS 8] [ NOV/DEC 2008].

10. (i) Discuss about the components of network management on the Internet. [MARKS 8] [ NOV/DEC2008].

(ii) Write short notes on symmetric-key cryptography. [MARKS 8] [ NOV/DEC 2008].

11.(i) Explain the salient features of the SMTP protocol. [12] [May/June 2009]

(ii) Consider accessing a web page consisting of 10 objects (assume that each object fits in 1 MSS)

using persistent HTTP. Draw a timeline diagram showing the transfer of data taking congestion control

into consideration. [4] [May/June 2009]

12. (i) Discuss the various commands used in FTP. [12] [May/June 2009]

(ii) What is the iead used in the public key encryption system? [4] [May/June 2009]

13. (i) Disscuss briefly the DNS in internet. [8] [Apr/May2010]

(ii) Explain the Simple Mail Transfer Protocol. [8] [Apr/May2010]

14. (i) Explain the various services provided by security. [8] [Apr/May2010]

(ii) What are the servers involved in Kerberos protocol? Explain in detail. [8]

[Apr/May2010]

15. Explain the SMTP and HTTP.give their uses,state strengths and weaknesses. [NOV/DEC 2010]

16. Explain the role of a DNS on a computer network. [NOV/DEC 2010]

17. Discuss in detail about DNS and its frame format(Nov/Dec 2011)

18. Explain SMTP in detail . (Nov/Dec 2011)

19. Explain the various process involved after typing the URL in the task bar(Nov/Dec 2012)

20. Wriite short notes on the following (Nov/Dec 2012)

EMAIL HTTP (World Wide Web)

21. Discuss the need for name resolution. Illustrate the domain name hierarchy and the steps in resolution.

(May/June 2013)

22.Illustrate the features of FTP and its operation. (May/June 2013)

23. Illustrate the features of TELNET. What is the need for network virtual terminal? (May/June 2013)