BSc. (Hons.) Computer Science with Network Security. Examinations for 2016 / Semester 2

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1 BSc. (Hons.) Computer Science with Network Security Cohort: BCNS/15A/FT Examinations for 2016 / Semester 2 MODULE: Network Programming MODULE CODE: CAN 2113C Duration: 2 ½ Hours Instructions to Candidates: 1. Attempt all 3 questions. 2. Answer each question on a separate sheet. 3. Annex 1 is attached with the examination paper. 4. Smartphone and calculator are not allowed. This question paper contains 3 questions and 8 pages. Page 1 of 8

2 QUESTION 1 (35 marks) Socket Programming + SSL + RMI (a) One way of programming client server applications is socket programming. Explain the role sockets, port numbers and IP addresses in an inter-process communication between a client and a server. State the key classes in socket programming with TCP and socket programming with UDP. (iii) What are the purpose of the following classes? HttpURLConnection InetAddress (b) Remote Method Invocation (RMI) is a purely Java technology for network programming. How does RMI differ from socket programming in the context of the client/server network programming model? Explain the use of the following classes in RMI. UnicastRemoteObject java.rmi.remote java.rmi.naming Page 2 of 8

3 (iii) Explain the purpose of the rmiregistry in RMI programming. (c) Figure 1.1 illustrates the Secure Socket Layer (SSL) architecture. Figure 1.1 Describe the function of the different SSL protocols. (4 x 3 marks) Give 1 example of a framework for SSL programming. (2 marks) Page 3 of 8

4 QUESTION 2 (30 marks) Multithreaded Programming (a) Multithreaded programming is network programming paradigm with multiple advantages like multiple clients communication amongst others. Differentiate between process based multitasking and thread based multitasking. What do you understand by context switching? (b) Explain the actions of the following methods on threads. notifyall() sleep ( 300) (iii) join( ) (iv) suspend () (v) wait( ) (5 x 1 marks) (c) Multithreading has a number of features making it robust in a network programming environment. Explain the consumer- producer problem. Which key word is used to avoid of conflict or deadlock in a multithreaded program dealing with sharing of resources or objects? Page 4 of 8

5 (iii) The In Java, each thread is assigned priority, which affects the order in which it is scheduled for running. i. Which is the default priority to all threads and on which scheduling scheme? ii. How would you set a thread object tr1 to maximum priority? (d) Refer to the coding in Annex 1. Perform a dry run and display the output of the program. (10 marks) Page 5 of 8

QUESTION 3 (35 marks) SDN / NFV (a) Distinguish between SDN and NFV. (5 marks) (b) Figure 3.1 depicts the architecture of a SDN network. Figure 3.1 Describe the components Northbound and Southbound.

6 QUESTION 3 (35 marks) SDN / NFV (a) Distinguish between SDN and NFV. (5 marks) (b) Figure 3.1 depicts the architecture of a SDN network. Figure 3.1 Describe the components Northbound and Southbound. How can SDN be beneficial to telco operators or data centers? You may use a diagram to support your answer. (iii) What are the advantages of separating the control plane and the data plane? Page 6 of 8

7 (iv) What is the role of the controller in SDN? (v) VLAN is an example of network function virtualization, state 2 more examples of NFVs. (c) The code below represents commands in mininet to model and study the network parameters of a SDN network. mininet@mininet-vm:~$ sudo mn --mac--controller=remote, ip= , port=663 topo tree,2 h1,h2,h3.h4,h5 s1,s2,s3 (h1,s1) (h2,s1) (h3,s1) (h4,s3) (h5,s3) (s1,s2) (s1, s3) h1 h2 h3 h4 h5 s1 s2 s3 mininet> Draw the topology of the network created. (2.5 marks) Explain the command: mininet@mininet-vm:~$ sudo mn --mac--controller=remote, ip= , port=663 topo tree,2 (2.5 marks) Page 7 of 8

8 (iii) Explain the command: sudo mn link dc,delay = 10ms,loss=5,max_queue_size=3 (2.5 marks) (iv) Display the output of this command. mininet> h1 ping h4 mininet> nodes mininet> net (2.5 marks) ***END OF QUESTION PAPER*** Page 8 of 8

BSc ( Hons) Computer Science with Network Security. Examinations for / Semester 2

BSc ( Hons) Computer Science with Network Security Cohort: BCNS/16B/FT Examinations for 2017 2018 / Semester 2 Resit Examinations for BCNS/15B/FT & BCNS/16A/FT MODULE: NETWORK PROGRAMMING MODULE CODE: