Solved question paper for CN May-2017 (BCA 4th)

Question paper 1

1. Section-A

   1. Describe the TCP/IP reference model and compare it with OSI reference model.

   Answer:

   1. TCP/IP Model:- It refers to transmission control protocol. It follows a horizontal approach for stop it can be connection oriented or connectionless.

   TCP/IP	OST
   it contains of four layers.	It contains 7 layers
   Uses loose layering result in horizontal layer	uses strict layering result in vertical layers
   Support Only connection less in the network layer but connectionless and connection oriented communication in transport layer.	Support both connectionless and connection oriented communication in the network layer but only connection oriented communication in transport layer.
   Does not clearly distinguish black and white service interface protocol	It distinguishes black and white service interfaces a protocol.
   Protocol are not hidden and thus cannot be replaced easily	Protocol are better hidden and can be replaced respectively easily and Technology charges.
   The protocol came first and the model was description of the exciting protocols.	OIS references model was dissolved before the corresponding protocol with the designed.
   This is an implementation of OS model	this is a references model
   Model around which internet is developed	This is article model

   So above the TCP model and comparison TCP/IP and OIS model

2. 2. (a)  what do you mean by broadcast transmission Technology? How is it different from point to point a transmission Technology.

   Answer:

   2. (a) Broadcast transmission technology:- It is a define as network that have a single communication channel that is shared or used by all machine on the network host of short messages called packet sent by any machine and received by all the other.

   Broadcast System generally used as special code in the address field of addressing a packet to all the concerned computers.

   Broadcasting is the distribution of audio or video connected to a depressed audience of via any electronic mass Communications medium.

   Broadcasting Network	Point to point Network
   single communication channel that is shared by all the machine on the network for stock	Many connections between individual pairs of Machines.
   All the other preview packets in contain contact centre by any machine.	Aap packet may have to visit one or more intermediate machine.
   An address field within the packet specifies for whom it is intended.	Routing algorithm play an important role in PTP network

   
    

3. (b) Describe any two important design Ishu for layer in a network architecture.

   Answer:

   (b) Design issue for layer in another network architecture ki design Ishu is a determining how packet are rooted for source the destination. roots can be passed on static table that are wired into the network and rarely changed full stop they can be highly dynamic being determined a new for each packet to reflect the current network load.

   It too many packets are present in the subnet and the same time they will get into another way forming bottlenecks. The control of such Conquestion also belong to the network layer.

   • the quality of service provided is also a network layer issues.

   • when a packet has to travel from one network to another to get to its destination many problems can arise a such as

   • The addressing used by the second network may be different from the first one.

   • The second one may not accept the packet at all because it is too large.

   • the protocol may differ and soon.

   • it is up to the network layer to overcome all the problem to allow heterogeneous network to be interconnected.

   •  

   so above are the design issue of network layer.

4. 3. Distinguishing between error control and flow control and explain one method is for error control and flow control.

   Answer:

   3. ERROR Control:- It include both error direction and error correction.

   It allowed the receiver to inform the sender if a Fame is lost on damaged during transmission and co-ordinate the retransmissions of those frames by the centre for stop

   Error Control the data link layer is passed on automatic repeat request. whenever an error is directed specified frames and are retransmitted.

   Flow Control:- Flow control co-ordinate the amount of data that can be sent before receiving acknowledgement.

   It Is one of the most important function of data link layer.

   It is a set of Producers that tells the sender how much data it can transmit before it must wait from acknowledgement from the receiver.

   receiver has a limit speed at which it can process Link data and a limited amount of memory in which to store incoming data is.

   Since the rate of processing is often slower than the rate of Transmission receiver has a block of memory for storing incoming data until they are processed.

   Flow control Techniques:- Stop and wait sliding window

   Stop and wait:- it is a concept of noiseless channel to It provide and directional data transmission without any error control facilities.

   ERROR control Techniques:- it is based on data link layer automatic repeat request which is Re transmission of data.

   ITR forms to error correction and Re transmission.

6. 4. Describe the following

   (a)  Connection oriented and connectionless service

   Answer:

   4. (a) Connection Oriented:- Prior connection need to be established for stop resources need to be allocated.

   It ensure reliable transfer of data

   Concession is not at all possible.

   It can be implemented either using circuit switching or BCS.

   It is it possible to reach transmit the last data brief. It is a suitable for long and shortly communication.

   Connection is established through process of signaling.

   These is more delay in transfer of information but once connection established faster delivery.

   Connection Less:- No-Prior connection is established.

   No-Prior allocation of resources is a required.

   Reliability is not quanted as it is a best effort service congestion can occur Likely.

   It is implemented using packet switching.

   It is not possible.

   It is it suitable for or transmission

   There is no concept of Signaling. in this packet reach the destination in a random manner.

   There isin no delay due absence of connection establishment phase.

   So, we can set that connection-oriented prior to standing packets belonging to the same message from source to destination and connectionless in which each packet belonging to the same message as a different and independent entity and route them with Different path.

7. (b) Local area and wide area network.

   Answer:

   (b) Local Area Network:- It is a group of network devices which allowed the communication between connected devices. the private ownership has the control over the local area network Rather than public. L A N has short propagation delete then m a n as well as w a n. It covers the smallest area such as college and school etc.

   • LAN Ownership is private. The speed of l a n is higher than a w a n. L a n design and maintenance is easy.

   • LAN covers smaller area within the building.

   • Transmission medium used in l a n is a CO axial or UTP cable.

   Wide area Network:- WAN cover the large area then l a n as well as m a n such as country continent etc. Wn is expensive and should or might not be owned by one organisation full stop pstn or satellite medium are used for wide area network for stock wn ownership can be private or public.

   • WAN is a slower than l a n. W and works on the principle of point to point. Whereas a w n user pstn or satellite link ok as a transmission of communication medium.

   • These is lesser fault to learn the w a n. It covers a large geographical area.

   so these are l a n and w a n descriptions.

8. Section-B

   5. What are the design issue of the network layer to the transport layer? Distinguishing between virtual circuit and datagram service of the network layer.

   Answer:

   5. Network Layer corresponds to the IP Layer in the TCP/IP world. the transport layer builds upon the network layers and can provide quality of service by providing error control. Sequence control flow control etc.

   1. Store and forward packet switching:- The host send a packet that store there until it has police arrived once the link is fully processed by verifying the check some to the nearest route.

   2. Service provided to transport layer:- Network layer provided its service to the transport layer 2 type of service connection less and connection oriented.

   3. Implementation of Connection Service:- When The message size that has to be transmitted is four times the size of a packet and the network layer divide into four packets and transmit each packet to router via a few protocol.

   4. Connection Oriented Service Implementation :- To use this service first we establish a connection use it and then release it.

   It can be done in other two ways

   circuit switched and virtual circuit switched connection.

9. 6. Describe any one algorithm for each of the following.

   (a) Routing 

   (b)  Congestion control 

   Answer:

   6. (a) Routing :- routing algorithm is a set of steps by steps operations used to direct internet traffic efficiently.

   Dijkstrias algorithm:-

   1. Instalization

   2. N'=(A)

   3. For all Nodes v

   4. If v adjacent to A

   5. Then D (V) =c

   6. Else D(V)=

   7. .

   8. Loop

   9. Find W not in N such that D (w) is minium

   10. Add W to N

   11. Update D(V)for all V adjacent to W and not in Np

   12. D (v) =min (D(v),D(W)+C(w.'))

   13. /* new cost to v is either the old cost or know shortest path cost to W plus cost from w to v*/

   14. Unstall nudes N

   (b) Congestion control :- A state occurring in network layer when the message traffic is a so heavy that it sends down network response time.

   Token bucket algorithm :-describ as follow

   (I) in the quarrel intervals token are thrown into the bucket

   (ii) the bucket has a maximum capacity

   (III) if there is a a ready packet a token is removed from the bucket and the packet is a send.

   (Iv) if there is no token in the bucket the packet cannot be send.

   Leaky bucket algorithm control the rate at which the packets are introduced in the matter but it is very conservation in nature full stop but some flexibility is introduced in token bucket algorithm.

   suit token bucket algorithm is superior to leaky bucket algorithm.

11. 7. Explain the design issue related with the transport layer and distinguishing between TCP and UDP.

    Answer:

    7. Design issues related to important layer

    1. addressing:- Every layer need a mechanism to sender and receiver.

    2. Error control :- It Is an important issue because a physical communication circuit are not perfect.

    3. Flow control :-This property leads to mechanism for this disassembling transmitting and reassembling messages.

    4. Multiplexing

    5. De-multiplexing

    6. Routing:- When there are multiple paths between source and destination a route must be Choose.

    accepting data from season layer split it into segments and send to the network layer.

    Ensure correct delivery of data with efficiency.

    Isolate upper layer from the technical changes.

    Error control and flow control.

    So above are the design Issue in transport layer.

    	TCP	UDP
    connection	Connection oriented	Connectionless
    Usage	High reliability critical lesser transmission time	Fast efficient transmission small query huge number of clients
    Ordering of data brackets	Rearrange brackets in order	No internet order
    Reliability	Yes	No
    streaming of data	Read as a byte stream	Sent and read individually
    error checking	recovery and error checking	No recovery simple error checking
    Acknowledgement	segments available	No acknowledgement

    
     

12. 8. What is the difference between Sub situation Ciphers and transposition ciphers? Give example of each type.

    Answer:

    8. Transposition Ciphers:- In a transposition there is no substitution of crackers instead there location change. A character is the first position of plain text may appear in the tenth position of hypertext. A character is the Earth position may appear in the first position. In other word Dad transposition cypher record the symbol in a block of symbols.

    Key in a transposition cypher Archi is a mapping between the position of the symbol in the plaintext and ciphertext.

    Example:- Plain text- 2413

    Cipher text- 1234

    In Encryption, we Muda character at position 2 to position 1 the character at position 4 2 position 2 2 and so on.

    In Decryption we do the reverse.

    Substitution Technique:- It involves the replacement of the letter by other letters and symbol. In more straightforward way. The character of printed and replaced and other substitute tractors number and symbol are used at their place.

    Cease Sniper used the substitution techniques of where the alphabet are replaced with the other alphabet where are the three position forward for the lives.

    So Substitution technique replace the character and substitution cypher is simpler and easy to break.

13. Section-C

    9. Answer any five of the following question in brief

    (I)  What is Metropolitan Area Network?

    Answer:

    9. (i) Metropolitan Area network:- A Metropolitan Area Network is a computer network that interconnects user with computer resources in my Geographic region of the size of Metropolitan Area. The term of m a n is applied to interconnect of local area network in a city into a single large electric which may then also offer efficiently connected to a wider area network a m a n term is also used as a server Local area network in a Metropolitan Area through the use of point to point connection between them.

    
     

14. (II) name any two network hardware component describe their purpose.

    Answer:

    (ii) Network Hardware Components:- A typical computer system consists of computer cases. A power supply unit mother a central Processing Unit had a hard disk drive. Input devices include a keyboard and mouse microphone video camera and imagesscanner.

    Output devices include a monitor speaker and printer.

    A typical Tower model is between 15 to 25 inches High.

16. (III) describe the unrestricted simple protocol for flow control.

    Answer:

    (iii) Unrestricted simplex protocol:- In order to appreciate the step-by-step development of efficiency and complex protocol we will being a simple but unrealistic Protocol. In this product for data are transmitted in One Direction on the.

    The transmitting and receiving host are Are always ready.

    Processing time can be ignored.

    Infinite buffer space is available.

    No error occurs for example no damage frames and low frames.

17. (Iv) what are the digital signature?

    Answer:

    (iv) Digital Signature:- Must depend on the messages is signed must use information unique to sender to prevent foreign and Denial must be relatively easy to produce a must be relatively easy to recognised and verify be computerization I feasible to forget.

    With new message for executing digital signature

    With digital signature for given messages

    Be practical some digital signature in storage.

18. (v) What is the role of URLs and web Browser in www? 

    Answer:

    (v) URLs:- It is a uniform resource locator. It is a a unique identifier user to locate a resource on the internet first of it is also referred to as a web address of. end User using URL se by typing them directly into the address bar of a browser or by clicking hyperlink found on the web page bookmark list in a email or form and other applications.

    Web browser:- It is A software application for accessing information on the world wide web. when a user request a particular website for stop the web browser relative the necessary content from a web server and then it display the resulting web page on the user device.

    A web browser is not the same thing as a search Unique . prove that two are often confused. For a user search engine is is just a website a such as a Google search being or duckduckgo.com full stop that store search able data about other website.

19. (Vi) what is the need of DNS in the internet?

    Answer:

    (vi) DNS:- Domain name servers are the internet equivalent of a phone book full so they maintain a directory of domain name and translate them to Interact protocol address. This is necessary because all the domain name are easy for people remember. Computer on machine. Assessor website based on IP address.

    DNS is a directory services that provide a mapping between the name of a host on the network and its numerical address.

    DNS required for the functioning of internet full stop this allowed the user of network to utilise user friendly name when looking for other host is instead of remembering the IP address.