CS8591 COMPUTER NETWORKS UNIT II MCQ

 

UNIT II DATA LINK LAYER AND MEDIA ACCESS

Introduction – Link-Layer Addressing – DLC Services – Data-Link Layer Protocols – HDLC – PPP - Media Access Control - Wired LANs: Ethernet - Wireless LANs – Introduction – IEEE 802.11, Bluetooth – Connecting Devices.

 

1. Refers to a set of procedures used to restrict the amount of data that the sender can send before receiving an acknowledgement from the receiver.

    A.    Flow control

    B.    Error control

Answer: A

 

2. Which of the following tasks is not done by data link layer?

    A.    framing

    B.    error control

    C.    flow control

    D.    channel coding

Answer: D

 

3. The sub layer that deals with all the issues which are common to both point-to-point and broadcast links

    A.    Data Link Control (DLC) Sublayer

    B.    Media Access Control (MAC) Sublayer

Answer: A

 

4. If a datagram is destined for only one destination (one-to-one delivery), then it is called

    A.    Unicast

    B.    Multicast

Answer: A

 

 

5. Maps IP address into logical address

    A.    RARP

    B.    ARP

Answer: B

 

6. In this framing, need a way to define the end of one frame and the beginning of the next. 

    A.    fixed-size framing

    B.    variable-size framing

Answer: B

 

7. A special byte is added to the data section of the frame when there is a character with the same pattern as the flag.

    A.    byte stuffing

    B.    Special stuffing

Answer : A

 

8. The last address of IP address represents

A. Unicast address

B. Network address

C. Broadcast address

D. None of above

Answer : C

 

9. A DLC protocol can be             

A.   either connectionless or connection-oriented

B.    Connection oriented

C.    connectionless

Answer: A

 

10. The ______ Protocol has neither flow nor error control.

A.   Selective-Repeat ARQ

B.    Go-Back-N ARQ

C.    Stop-and-Wait

D.   Simple

Answer: D

 

11. In normal response mode (NRM), the station configuration is

A.    Balanced

B.    unbalanced

Answer: B

 

12. In HDLC these frames are reserved for system management

A.    I frames

B.    S frames

C.    U frames

Answer: C

 

13. In HDLC supervisory frames are used to

A.    transport control information

B.    transport management information

Answer: A       

 

14. In I frames, When the frame is sent by a primary station to a secondary, it is represented as

A.    final

B.    poll

Answer: B

 

15. In the control field for S frames, If the value of the code subfield is 11, it is an

A.    SREJ Sframe

B.    REJ S-frame

C.    RNR Sframe

Answer: A

16. In Password Authentication Protocol(PAP) The value of the protocol field is

A.    0xD023

B.    0xC023

C.    0xB023

Answer: B

 

17. In transition phases of Point to Point protocol, if authentication is successful then connection transfers to

A.    Open phase

B.    networking phase

C.    terminating phase

Answer: B

 

18. CHAP provides greater security than the

A.    Network Control Protocol

B.    Link Control Protocol

C.    Password Authentication Protocol

Answer: C

 

19. In this protocol, there is no particular scheduled time for a station to transmit and the transmission is random among the stations

A.    Controlled access

B.    Random access

C.    Channelization protocols

Answer: B

 

20. The maximum throughput for the pure Aloha is

A.    0.184

B.    2.2

C.    none of the above

Answer: A

21. In the ________method, a station that has a frame to send senses the line. If the line is idle, it sends immediately. If the line is not idle, it waits a random amount of time and then senses the line again.

A.    1-persistent

B.    nonpersistent

C.    p-persistent

Answer: B

 

22. In CSMA/CD, At this level, there is a collision and the level of the energy is twice the normal level.

A.    zero level

B.    normal level

C.    abnormal level

Answer: C

 

23. This method is used if the channel has time slots with a slot duration equal to or greater than the maximum propagation time. It also combines the advantages of other two methods

A.    1-persistent

B.    nonpersistent

C.    p-persistent

Answer: C

 

24. When an idle channel is found, the station does not send immediately. It waits for a period of time called the

A.    Idle Space

B.    interframe space

Answer: B

 

25. When the station accesses the system and send a Request to Send (RTS) frame then other stations start their

A.    Clear to send

B.    Network Allocation Vector

C.    Point coordination function

Answer: B      

 

26. It works with topologies in which one device is designated as a primary station and the other devices are secondary stations

A.    Polling

B.    Token passing

C.    reservation

Answer: A

 

27. In this topology, when a station sends the token to its successor, the token cannot be seen by other stations;

A.    Physical ring topology

B.    Dual ring topology

C.    Bus ring topology

Answer: A                  

 

28. The available bandwidth of the common channel is divided into bands that are separated by guard bands.

A.    FDMA

B.    CDMA

C.    TDMA

Answer: A

                        

29.  In _______, the sequences are generated using orthogonal codes such the Walsh tables.

A)   TDMA

B)   CDMA

C)   FDMA

Answer: B

 

30. In _____, each station is allocated a time slot during which it can send data. Each station transmits its data in its assigned time slot.

A)   TDMA

B)   CDMA

C)   FDMA

Answer: A

 

31. The original Ethernet technology with the data rate of 10 Mbps as the

A.    Standard Ethernet.

B.    Fast Ethernet

Answer: A

 

32. The Maximum frame length of Standard Ethernet is

A.    64 bytes

B.    1500 bytes

C.    1518 bytes

Answer: C

                                   

33. 10 Base 2 implementation is also called as

A.    Cheapernet

B.    Thicknet

Answer: A

                          

34. Gigabit Ethernet has a data rate of ______ Mbps

A.    10

B.    100

C.    1000

Answer: C

 

35. In Ethernet, if the least significant bit of the first byte is 0, the address is

A.    Unicast

B.    Multicast

C.    broadcast

Answer: A

 

36. A basic service set without an access point is a stand alone network called

A.    Cellular network

B.    Point to point network

C.    Adhoc network        

Answer: C

 

37. A station with mobility is either stationary (not moving) or moving only inside a BSS.

A.    no-transition

B.    BSS-transition and

C.    ESS-transition

Answer: A

 

38. To give priority to Point Coordination Function over DCF, another interframe space, has been defined.

A.    PIFS

B.    IPFS

Answer: A

 

39. These frames are used for the initial communication between stations and access points.

A.    Control Frames

B.    Management Frames

C.    Data Frames

Answer: B

 

40. These frames are used for carrying data and control information

A.    Control Frames

B.    Management Frames

C.    Data Frames

Answer: C

 

41. A piconet can have up to ____stations

A.    six

B.    Eight

C.    Seven

Answer: B

 

42. A piconet can have a maximum of seven secondaries, additional secondaries can be in the ____ state

A.    Rest

B.    Closed           

C.    Parked

Answer: C

 

43. Multiple piconets form a network called a

A.    Network allocation vector

B.    scatternet

C.    largenet

Answer: B

 

44. The L2CAP has specific duties:

A.    Multiplexing

B.    segmentation and reassembly

C.    quality of service (QoS), and

D.    group management.

E.     all the above

Answer: E

 

45. Bluetooth technology was originally started as a project by the

A.    ericsson company

B.    Samsung company

C.    none of the above

Answer: A