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NATIONAL OPEN UNIVERSITY OF NIGERIA
UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
JANUARY/FEBRUARY 2013 EXAMINATION
Course Code: CIT 311 Time: 3hrs
Course Title: Computer Networks Course Credit Unit: 3
Instruction: Answer any five (5) questions.
QUESTIONS
1a. State four (4) requirements for an efficient traffic control mechanism. (16 marks)
1b. Briefly explain the concept of ring topology. (4 marks)
2. Specify the main function of the following:
- Datagrams
- Bridges )
- Transport Layer ) 5 marks each
- Repeaters
- Routers
3. As an expert in Internet applications, identify any ten (10) features of the electronic mail.
4a. Describe how the ATM protocol works. (16 marks)
4b. Give a good reason why asynchronous transfer modes are considered appropriate for multimedia communication. (4 marks)
5a. State any five (5) tasks which a modem can perform. (10 marks)
5b. Based on your knowledge of computer networks, give the meaning of the acronym RIP. (1 mark)
5c. Describe three (3) common problems that can occur in RIP. (9 marks)
6. Generally, modem indicator lights can be found in different states. Indicate the status of the modem indicator light in the following settings:
6a. When receiving a call. (5 marks)
6b. If the modem is sending data. (5 marks)
6c. When the modem detects the remote modem’s carrier. (5 marks)
6d. If the computer is ready to send or receive data. (5 marks)
7b. Write five (5) common applications of Integrated Services Digital Network (ISDN) (10 marks)
7a. Distinguish between Baseband and Broadband Communication. (10 marks)
