Question bank cn2


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Question bank cn2

  1. 1. UNIT I :PACKETING NETWORKS I 1. What are datagram and virtual circuits? Distinguish between them. 2. Explain and derive delays in datagram packet switching 3. Why is packet switching more suitable than message switching for interactive applications? Compare the delays in datagram packet switching and message switching. 4. Compare the Bellman ford algorithm and dijkstra’s algorithm for finding the shortest paths from a source node to all other nodes in a network. a. Suppose that 64kbps PCM coded speech is packetized into a constant bit rate ATM cell stream What is the interval between production of full cells? b. How long does it take to transmit the cell at 155 Mbps? c. How many cells could be transmitted in this system between consecutive voice cells? 5. 6. Explain the working mechanism of following devices used to connect LANs. a. Bridge b. Router 7. Explain the working of a LAN bridge. Clearly explain how a transparent bridges sets-up ‘its’ table entries. 8. Explain the “store and forward” packet switching used to send a packet from the source to the destination.UNIT II PACKETING NETWORKS II AND TCP/IP 1. With a neat diagram explain leaky bucket policy 2. Explain the following fields in the IP packet header a. Time to live b. Fragment offset c. Header checksum 3. A large number of consecutive IP addresses are available starting at Suppose that 3 organizations A,B & C request 4000, 2000 and 1000 addresses respectively and in that order. For each of these, give the first IP address assigned, the last IP address assigned and the mark in the w.x.y.z/s notation. 4. Explain the three way handshake for establishing a TCP connection 5. Explain the FIFO and priority queue scheduling for managing traffic at packet level 6. Explain the leaky bucket algorithm for policing the traffic at flow level 7. Consider a packet-by-packet fair queuing system with three logical buffers and with a service rate of one unit/second. Show the sequence of transmissions for this system for the following packet arrival pattern: a. Buffer1: arrival at time t=0, length=2, arrival at t=4, length=1 b. Buffer2: arrival at time t=2, length=3, arrival at t=2, length=1 c. Buffer3: arrival at time t=3, length=5 8. An university has 150 LANs with 100 hosts in each LAN a. Suppose the university has one class B address. Design an appropriate subnet addressing scheme. b. Design an appropriate CIDR addressing scheme. 9. Explain the implementation of connection – oriented service through an example (on a subnet) 10. Compare connection-less and connection oriented service with respect to the following metrices. a. Circuit setup b. Addressing
  2. 2. c. Maintaining state information and d. Routing and router failures 11. Explain any four properties desirable in a routing algorithm 12. Explain how folding can be used as a routing algorithm. What are the problems associated with it? How can they be prevented? 13. Explain the salient features of the TCP header fields. 14. Write short notes on any four. a. Need for ATM b. IP over ATM c. The leaky bucket algorithm d. IP addressing e. Subnetting. 15. Explain the leaky bucket technique for policing, with an appropriate diagram.UNIT III TCP/IP 2 1. Explain the IP address classification. Identify the following IP addresses and their address class: a. b. c. d. 2. Give the format of IPV6 basic header. Explain the importance 3 Explain in detail, the operation of OSPF. 4 Explain identification, flags and fragment offset field in the IP version 4 header. 5 What is the need to change from IPV4 to IPV6? Write the IPV6 basic header and describe its fields. 6 Describe how TCP establishes the connection using a three way handshake procedure. 7 What is routing information protocol(RIP)? What is the maximum width of a RIP network?UNIT IV ATM NETWORKS 1. With a neat diagram explain the ATM cell header format 2. write a short note on AALI 3. explain the PNNI signaling with example. 4. Give the structure of ATM cell header and details of QOS parameters 5. What are the six QOS performance parameters in ATM? 6. What is ATM adaptation layer type 1(AAL1)? Describe the generic AAL1 process. 7. Describe PNNI signaling with an example. 8. What are the design goals of ATM? Briefly describe ATM layers 9. Write short notes on: a. Management information base b. Cipher feedback concept c. Leaky bucket vs. Token bucket algorithm d. SNMP
  3. 3. UNIT V NETWORK MANAGEMENT, SECURITY 1. Apply RSA and do the following a. Encrypt a=3 b=11, x=3 and m=9 b. Find the corresponding y c. Decrypt the cipher text 2. Explain in detail, any two major categories of threat to network security 3. Which are the different data types used in the structure of management information? 4. Give the comparison between public key and secret key crypto graphic systems 5. What are the functions performed by a network management system? 6. What are SNMP, SMI and MIB? 7. Explain the RSA algorithm. Using it, encrypt the following: a. P=5, q=11, e=7, p=18 8. Why is digital signature used and what are the properties of digital signature? 9. Describe briefly DES algorithm used for encryption 10. Write short notes on: 1) fire walls. 2) SSL 11. Explain Diffie Hellman key exchange algorithm with example. 12. Describe authentication using Kerberos 13. Justify how PGP is efficient in achieving E-mail security. 14. What are the components of network management and list their functions. 15. What are the desirable properties to secure communication? Explain briefly. 16. Write a note on DES 17. Define the terms and explain the following: a. Authentication b. Digital Signature c. RSA algorithm d. Fire wall 18. Explain security and administration of SNMPV3. 19. Write short notes on: a. IMAP b. RTP 20. What is DES? How does it work? Explain. 21. Briefly describe the encryption model for a symmetric key cipher. 22. Write short notes on: a. SNMP protocol b. Management information base. c. H.323 architecture for internet telephony d. Firewalls. 23. Define the following terms: a. Confidentiality b. Authenticity c. Integrity d. Non repudiations e. Cryptanalysis and f. Intruder
  4. 4. 24. Name and explain the different steps of a public key cryptographic system that can be used to encrypt and decrypt symmetric keys? 25. Consider a group of ten people where every person in the group needs to communicate with every person in the group needs to communicate with every other person in another group of ten people. a. How many secret keys are needed considering? i. Symmetric key cryptography? ii. Asymmetric key cryptography? b. What are the values for the above cases, if every person in a group of ten people needs to communicate with every other person in the group? 26. Explain with an appropriate example, an asymmetric key cryptographic system that can provide one time session key to the end users and discuss about its demerits? 27. Name the different servers used in Kerberos protocol. Bring out role of each server and their functions in achieving authentication? 28. Consider Diffie and Hellman key exchange protocol where n and g are two public random numbers. Given : n=23 and g=7, what is the value of the symmetric key if x=3 and y=7? 29. Explain the JPEG technique for compressing continuous tone still pictures. 30. Explain the desirable properties of secure communication 31. Using RSA, choosing P=3, q=11 and d=7, encode the phrase “HELLO”. Apply the decryption algorithm to the encryption version to recover the original plain text message. 32. Assume a=1, b-2, ------ z=26. 33. What is denial of service attack? Explain, with an example. 34. Explain with a neat diagram, the principal components of a network management architecture. 35. Explain the importance features of RTP protocol and RTP packet header. 36. Write short notes on: 1) Firewall 2) HTTP 3) Real Time streaming protocol 4) Data encryption standard.UNIT VI QoS, Resource Allocation, VPNs, Tunneling, Overlay Networks 1. write a short note on SNMP 2. Explain the operation of fair queuing scheduler in context with packet scheduling of integrated service. 3. Explain the various types of resource allocation schemes. 4. Discuss the concept of tunnel and point to point protocol in context with UPN. 5. Explain VPN and its types based on tunneling 6. Explain the need for overlay networks and P2P connection
  5. 5. 7. Discuss the classification of resource allocation schemes. 8. What is a virtual private network (VPN)? Mention the different types of VPN and benefits of deploying a VPN. 9. What is an MPLS network? Explain MPLS operation 10. Explain the importance features of SSL. Explain the working of SSL, in detail. 11. Explain in detail, the working of IP security protocol.UNIT VII COMPRESSION OF DIGITAL VOICE AND VIDEO, VOIP, MULTIMEDIANETWORKING 1. Design a Huffman encoder for a source generating (a1,a2,a3,a4,a5,a6,a7} and with probabilities {0.05,0.1,0.1,0.15,0.25,0.3} 2. Explain in brief SIP 3. Explain in brief the structure of a SCTP packet 4. Explain the JPEG compression method and still image processing 5. Explain the session initiation protocol 6. Explain the typical JPEG process for production and compression of still images. 7. Design a Huffman encoder for a source generating {a0,a1,a2,a3,a4,a5,a6} corresponding probabilities {0.55, 0.10, 0.05, 0.14, 0.06, 0.08, 0.02} 8. What is RTSP? How is it used in multimedia network applications? 9. Explain the three broad classes of multimedia applications 10. What are the hurdles for multimedia? 11. Explain the types of redundancy in video compression 12. What are the differences between H.261 and H.263 13. Explain the three limitations of the best effort service 14. With suitable example explain RTSP messages exchanged between media player and server 15. Explain multimedia file format 16. Explain the JPEG technique for compressing continuous tone still pictures.UNIT VIII MOBILE AD-HOC NETWORKS, WIRELESS SENSOR NETWORKS: 1. Explain the following a. CGSR of Ad-hoc networks b. Types of attack in Ad-hoc networks. 2. Briefly explain direct and multi hop routing of intracluster routing protocol with the help of relevant diagram. 3. Write a short note on Zigbee technology. 4. With an example, explain the dynamic source routing protocol. 5. List the security issues in ad-hoc networks. Explain types of attacks. 6. What are Ad-hoc networks? Mention their application types and unique features 7. Explain the structure of a typical sensor node. 8. What are the advantages of the DEEP clustering protocol?