NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
APRIL 2019 EXAMINATION

COURSE CODE: CIT 722

COURSE CREDIT: 3

COURSE TITLE: COMPUTER NETWORKS

TIME ALLOWED: 2 ¹/₂ HOURS

INSTRUCTION: ANSWER QUESTION ONE (1) AND ANY OTHER FOUR (4)  QUESTIONS

QUESTIONS         

1a.       You have just been invited as a Guest Speaker in a conference for Network Administrators. Your role is to describe with the aid of relevant diagrams, any two (2) classes of network topology, highlighting the key benefit of each class. Write a short note for this presentation at the conference. (9 marks)  

1b.       State how networks are classified on the basis of their connection types.  (2 marks)

1c.       Based on the lessons learnt from the course material on Computer Networks, discuss how a network can be certified as an effective network.               (9 marks)

1d.       Give a brief explanation of the concept of ‘Routers’.   (2 marks)

[Total = 22 marks]

2a.       TCP and UDP are the most widely used protocols that are built on the top of an Internet Protocol (IP). State any five (5) distinctions between these two protocols. (10 marks)

2b.State the main signicance of the Transmission Control Protocol and Internet Protocol. (TCP/IP)  (2 marks)

  [Total = 12 marks]

3a.Describe with the aid of a diagram, how proxy servers protect the computer network.      (7 marks)

3b.       Mention and briefly explain five (5) ways in which data is transferred in computer networks.  (5 marks)

[Total = 12 marks]

4a.       Write short notes on the following: ( i ) Peer-Peer networks

 (ii) Server-based networks

 (iii) Pipelining )2 marks each; 2x5=10 marks

(iv) Encoder

(v)  Decoder

4b.       A common acronym in computer networks is ‘DHCP’. Give the full meaning of this acronym and a concise description of this acronym. (2 Marks)  

 [Total = 12 marks]

5a.       Generally, in computer networks, computers are organised in two different ways: in terms of their Domains and Workgroups. State any five (5) distinctions between a Domain and a Workgroup. (10 marks)

5b.Give a brief explanation of the concept of ‘Decryption’ in computer networks.(2 marks)

[Total = 12 marks]

6.         With the aid of a well-labelled diagram, describe the four (4) components of the TCP/IP model.           

    [Total = 12 marks]