Overview of Data Communication

1. The ____________ is the physical path over which a message travels.
a. Protocol
b. Medium
c. Signal
d. All the above

2. The information to be communicated in a data communications system is the _________________
a. Medium
b. Protocol
c. Message
d. Transmission

3. Frequency of failure and network recovery time after a failure is measures of the _______________ of a network.
a. Performance
b. Reliability
c. Security
d. Feasibility

4. An unauthorized user is a network ____________ issue.
a. Performance
b. Reliability
c. Security
d. All the above

5. Which topology requires a central controller or hub?
a. Mesh
b. Star
c. Bus
d. Ring

6. Which topology requires a multipoint connection?
a. Mesh
b. Star
c. Bus
d. Ring

7. Communication between a computer and a keyboard involves _______ transmission.
a. Simplex
b. Half-duplex
c. Full-duplex
d. Automatic

8. In a network with 25 computers, which topology would require the most extensive cabling?
a. Mesh
b. Star
c. Bus
d. Ring

9. A television broadcast is an example of ____________ transmission.
a. Simplex
b. Half-duplex
c. Full-duplex
d. Automatic

10. A _____________connection provides a dedicated link between two devices.
a. Point-to-point
b. Multipoint
c. Primary
d. Secondary

11. In a ____________ connection, more than two devices can share a single link.
a. Point-to-point
b. Multipoint
c. Primary
d. Secondary

12. In a transmission, the channel capacity is shared by both communicating devices at all times.
a. Simplex
b. Half-duplex
c. Full-duplex
d. Half-simplex

13. A cable break in a ___________ topology stops all transmission.
a. Mesh
b. Bus
c. Star
d. Primary

14. Which organisation has authority over interstate and international commerce in the communications filed?
a. ITU-T
b. IEEE
c. FCC
d. ISO

15. The Internet model consists of ____________ layers.
a. Three
b. Five
c. Seven
d. Eight

16. The process-to-process delivery of the entire message is the responsibility of the ___________ layer.
a. Network
b. Transport
c. Application
d. Physical

17. The _____________ layer is the layer closest to the transmission medium.
a. Physical
b. Data link
c. Network
d. Transport

18. Mail services are available to network users through the ___________ layer.
a. Data link
b. Physical
c. Transport
d. Application

19. As the data packet moves from the lower to the upper layers, headers are_________
a. Added
b. Subtracted
c. Rearranged
d. Modified

20. As the data packet moves from upper to lower layers, headers are____________
a. Added
b. Removed
c. Rearranged
d. Modified

21. The __________ layer lies between the network layer and the application layer.
a. Physical
b. Data link
c. Transport
d. None of the above

22. Layer 2 lies between the physical and the _______________ layer.
a. Network
b. Data link
c. Transport
d. None of the above

23. When data are transmitted from device A to device B, the header from A’s layer 4 is read by B’s _____________ layer.
a. Physical
b. Transport
c. Application
d. None of the above

24. The _________________ layer changes bits into electromagnetic signals.
a. Physical
b. Data link
c. Transport
d. None of the above

25. The physical layer is concerned with the transmission of ___________ over the physical medium.
a. Programs
b. Dialogs
c. Protocols
d. Bits

26. Which layer functions as a liaison between user support layers and network support layers?
a. Network
b. Physical
c. Transport
d. Application

27. What is the main function of the transport layer?
a. Node-to-node delivery
b. Process-to-process delivery
c. Synchronization
d. Updating and maintenance of routing tables

28. Which of the following is an application layer service?
a. Remote log-in
b. File transfer and access
c. Mail service
d. All the above
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