Electronics Systems and Technologies Q&A (For EcE)

1  Modulation is the process of sending a file from one computer to another computer.

                 False

2  Error correction and detection  in OSI model is done by

                 Data link Layer , Transport Layer

3 The functions of ATM layers are

                 Routing , Switching ,Multiplexing

4 The virtual circuit approach of packet switching is used in

                 Data Link layer

5 ATM standard defines ________ layer.

                 Three

6 Repeater operates in

                 Physical layer

7 A hub is actually

                 A multiport repeater

8 A central computer surrounded by one or more satellite computers is called a bus network.

                 False

9 Which of the following connects LAN to a WAN?

                 A network gateway

10 Devices on one network can communicate with device on another network via a gateway.

                 True

11Error control is based on

                ARQ

12 Transition states of PPP are

                 Idle state , Establishment state , Authenticating state

13 Transport layer is responsible for delivery of ________ from     one node to other.

                 Message

14 Packets in the IP layer are called

                 Datagrams

15 The primary function of a bridge is to

                 Interconnect two LANs

Full – duplex           = Simultaneous transmission in both directions

Modem                   = Modulator Demodulator

Bit                           = Binary digit Binary digit

Synchronous

communication

efficiency                 = High Band width of the medium

16 The application layer of a network consists of software being run on

     the computer connected to the network.

                True

Multiplexing                           = FDM

Bounded Media                    = Fiber optic cable

Wireless Transmission         = Microwave

Highest Attention                  = UTP cable

17Which of the following connects LAN to another of the same type?

                 A network bridge

18A remote bridge

                Useful for several offices with LANs , Acts as point-to- point link , Uses PPP protocol

               

19 The communication mode that supports two-way traffic but only one direction at a time is known as half duplex. 

                 True

20 The size of the datagram is

                 8 bytes

21 The layer lies between the network layer and the session          layer is

                Transport layer

22 The digital, voice, or video voltages are referred to as ____ signals.

                Base band

23 OSPF features are

                Multiple circuit load balancing , Converge very quickly to network topology change , Not susceptible to routing                 loops

24 Contention is

                The condition when two or more stations attempt to use the same channel at the same time

25 A communication protocol always have ________.

                 Set of symbols

26 A transport layer

                 Receives Service from Network layer , Gives service to Application layer

27 X . 25 protocol

                Allows DTE to DCE interface , Is a synchronous interface , Is approved by CCITT

28 The 5-7 digits are known as the country code of the Network User Address (NUA)

                False

29 As the data packet moves from the lower to the upper layers, headers are

                 Added

30 X.25 uses

                Packet assembler/disassembler , Packet switched network ,  Access lines to public data networks

31 For connecting several LANs, backbone networks are used.

                 True

32 Data rates above the 20,000 bps limitation of the RS-232 standard become possible by

                Shortening the cable

33 The medium that permits the highest data rate is ________.

                Fiber optic cable

34 The ________ Timer is used in termination phase.

                 Time waited

35 Internet protocol is a

                Host-to-host delivery network layer protocol

36 Network layer is responsible for delivery of ________ from one source to other.

                Packets

37 Gateway is used for modulation and demodulation.    False

38 ARQ stands for

                Automatic repeat request

39 Query message that ICMP supports

                Echo request and reply , Timestamp request and reply , Router solicitation and advertisement

40 Which organisation has developed much of the original standards?

                IEEE

41 The ________ timer keep a track of the time between the sending of segment and the receipt of an acknowledgement.

                Retransmission

42 The important features of a repeater are

                Can use 10Base5 , Acts as two port node , Operates     only in physical layer

43 A medium access control technique for multiple access transmission media is amplitude.                   

                 False

44 The X.25 standard covers ________ OSI layers.

                 3

45The available BW is divided into bands is

                 FDMA

46 Digital transmission is possible in

                 Serial mode , Parallel mode

47 Network File System (NFS) allow computers to share files across a network or networks.

                 True

48 Serial transmission can be

                 Synchronous , Asynchronous

49 Transmission media is characterized by

                 Throughput , Propagation speed , Propagation time

Time waited timer                  = Termination phase

Keep Alive Timer                   = Prevents long idle connection

Persistence timer                   =  Handles zero window size

Retransmission timer            =  Lost segments

50 The datagram approach of packet switching is used in

                 Network layer