MCQ On Data Communication Services Part-1

This set of MCQ questions on data communication services includes the collection of multiple-choice questions on the fundamental data communication services. It includes objective type questions on the examples of data communication services, circuit-switched data network, advantages of X.25 and the advantages of frame relay.

1. Which of the following is/are the examples of data communication services.
i) SMDS ii) Frame relay iii) X.25 iv) ATM
A) i, ii and iv only
B) i, ii and iii only
C) i, iii and iv only
D) All i, ii, iii and iv only

2. ……………. was developed in 1970 by CCITT for providing an interface between the public packet-switched network and their customers.
A) SMDS
B) Frame relay
C) X.25
D) ATM

3. X.25 protocol is based on the protocols used in early ……………. networks such as ARPANET, DATAPAC, TRANSPAC etc.
A) Packet Switching
B) Circuit Switching
C) Virtual Packet Circuit Switching
D) Virtual Packet Switching

4. ……………. protocol is a physical layer protocol is used to specify the physical electrical and procedural interface between host and network.
A) X.25
B) X.21
C) SMDS
D) X.23

5. ……………… is a connection-oriented service which supports switched virtual circuits as well as the permanent circuits.
A) X.25
B) X.21
C) SMDS
D) ATM

6. In X.25, ……………… is established between a computer and network when the computer sends a packet to the network requesting to make a call a packet to the network requesting to make a call to another computer.
A) Virtual circuit
B) Switched circuit
C) Switched virtual circuit
D) Switched intelligent circuit

7. In order to allow the computers who do not use the X.25 to communicate with the …………………., a packet assembler disassembler (PAD) is used.
A) X.21
B) SMDS
C) Frame relay
D) X.25

8. The layers defined by X.25 interface is/are
i) physical layer ii) data link layer iii) packet layer iv) application layer
A) i, ii and iv only
B) i, ii and iii only
C) i, iii and iv only
D) All i, ii, iii and iv only

9. The X.25 defines the interface for the exchange of packets between the
user’s machine (DTE) and the packet switching node to which this DTE is
attached which is called as …….
A) DCE
B) DDE
C) DLC
D) HDL

10. At the physical level, …………… physical interface is being used which is defined for the circuit-switched data network.
A) X.25
B) X.21
C) Frame relay
D) SMDS

11. The virtual circuit service of X.25 provides for two types of virtual circuits which are ………….
i) virtual circuit ii) permanent virtual circuit iii) permanent virtual call iv) virtual call
A) i and ii only
B) ii and iii only
C) iii and iv only
D) ii and iv only

12. A ………………….. is a dynamically established virtual circuit using a call setup and call clearing procedure.
A) Permanent virtual circuit
B) Virtual call
C) Virtual circuit
D) Permanent virtual call

13. A ……………… is a fixed network assigned virtual where data transfer takes place as with virtual calls, but no call setup or clearing required.
A) Permanent virtual circuit
B) Virtual call
C) Virtual circuit
D) Permanent virtual call

14. Which of the following is/are the advantages of X.25
i) Frame delivery is more reliable ii) X.25 is faster than Frame relay iii) Frames are delivered in order iv) Flow control is provided

A) i, ii and iv only
B) i, ii and iii only
C) i, iii and iv only
D) All i, ii, iii and iv only

15. ……………… is a connection-oriented service, which can be imagined to be equivalent to a virtual leased line.
A) X.25
B) Frame relay
C) SMDS
D) ATM

16. ………………. does not provide acknowledgments or normal flow control.
A) Frame relay
B) X.25
C) SMDS
D) ATM

17. ………….. was developed for taking advantage of the high data rates and low error rates in the modern communication system.
A) X.25
B) Frame relay
C) SMDS
D) ATM

18. In …………….. the cell control packets are used for setting up and clearing virtual circuits.
A) ATM
B) X.25
C) SMDS
D) Frame relay

19. Which of the following is/are the advantages of frame relay.
i) streamlined communication process ii) lower delay iii) higher throughput
A) i and ii only
B) ii and iii only
C) i and iii only
D) All i, ii and iii

20. In ……………. the number of functions of a protocol at the user network interface is reduced.
A) X.25
B) Frame relay
C) SMDS
D) ATM

Answers

1. D) All i, ii, iii and iv only
2. C) X.25
3. A) Packet Switching
4. B) X.21
5. A) X.25
6. C) Switched virtual circuit
7. D) X.25
8. B) i, ii and iii only
9. A) DCE
10. B) X.21
11. D) ii and iv only
12. B) Virtual call
13. A) Permanent virtual circuit
14. C) i, iii and iv only
15. B) Frame relay
16. A) Frame relay
17. B) Frame relay
18. D) Frame relay
19. D) All i, ii and iii
20. B) Frame relay