chapter 4 (2) Flashcards by Moon Le

What is the primary function of the “Message Delineation” function in the Data Link Layer?
a) Determining the speed of data transmission
b) Identifying where a message starts and stops
c) Controlling the flow of data within the network
d) Deciding the priority of different types of messages

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____________ is not a function of a data link protocol.
a. Media access control
b. Message delineation
c. Amplitude shift keying
d. Indicating when a message starts and stops
e. Error control

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Which of the following functions does the Data Link Layer perform?
a) Adds a Protocol Data Unit (PDU) called a packet to the received frame.
b) Adds a Protocol Data Unit (PDU) called a frame to the received packet from the network layer.
c) Adds a Protocol Data Unit (PDU) called a segment to the received packet from the transport layer.
d) Adds a Protocol Data Unit (PDU) called a segment to the received frame.

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What is the primary purpose of the frame added by the Data Link Layer to the received packet?
a) Enhancing network performance
b) Ensuring message delineation and error control
c) Increasing data transfer speed
d) Enabling end-to-end communication

B. This frame includes necessary information for message delineation and error control.

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Asynchronous transmission:
a. is used to transmit each character simultaneously with all other characters
b. has a pre-determined, fixed time between sending characters
c. is typically used on multipoint half duplex circuits
d. uses a continuous series of start bits as an idle signal
e. is also known as start-stop transmission

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Which of the following is an example of a protocol that uses asynchronous transmission?
a) HTTP
b) FTP
c) VT100
d) TCP

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How many bits are typically used for the transmission of each character in asynchronous transmission with 7-bit ASCII and even parity?
a) 7 bits
b) 8 bits
c) 9 bits
d) 10 bits

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In asynchronous transmission, what signal is sent down the circuit when no data is being transmitted?
a) Start bit
b) Stop bit
c) Idle signal
d) Parity bit

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What does the start bit indicate in asynchronous transmission?
a) End of character
b) Start of character
c) Data transmission complete
d) Data error detected

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Which type of circuit is asynchronous transmission typically used on?
a) Point-to-point half-duplex circuits
b) Point-to-point full-duplex circuits
c) Multi-point half-duplex circuits
d) Multi-point full-duplex circuits

B. media access control is not a concern

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How is the idle signal defined in asynchronous transmission?
a) Same as the start bit
b) Same as the stop bit

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Which protocols have traditionally used asynchronous transmission?
a) HTTP and FTP
b) TCP/IP and UDP
c) VT100 and Telnet
d) SSH and SSL

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Which of the following is not a type of synchronous protocol?
a. SDLC
b. VT100
c. HDLC
d. Ethernet
e. PPP

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Synchronous transmission:
a. cannot be used on multipoint circuits
b. is used to send one character at a time
c. uses start bits before each character to be sent
d. uses stop bits after each character to be sent
e. is used to transmit a “frame” or “packet” of data at a time

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How are data typically sent in synchronous transmission?
a) Independently of each other
b) In small packets
c) In a large block called a frame
d) Through continuous streams

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What is included in a frame in synchronous transmission?
a) Only data bits
b) Only media access control information
c) Addressing information and media access control
d) Only synchronization characters

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What purpose do synchronization (SYN) characters serve in synchronous transmission?
a) To indicate the end of a frame
b) To identify the receiver
c) To help the receiver recognize the beginning of a frame
d) To encrypt the data being transmitted

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How many SYN characters can be present at the start of a frame in synchronous transmission?
a) One
b) Four
c) Six
d) Eight

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Approximately how many bits can a frame contain in synchronous transmission?
a) Hundreds
b) Thousands
c) Tens
d) Millions

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In which type of circuit is synchronous transmission typically needed?
a) Point-to-point circuits
b) Multipoint circuits
c) Wireless circuits
d) Analog circuits

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Which of the following is true about the data link protocol, SDLC:
a. It is a client-server protocol developed by Compaq in 1996
b. It is a byte-count-oriented protocol
c. It uses a special bit pattern called a flag at the beginning and end of every frame (or
packet)
d. It uses a contention media access control protocol
e. It does not have a problem with transparency

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Synchronous transmission cannot be used on multipoint circuits.

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Who developed the Synchronous Data Link Control (SDLC) protocol?
a) Apple Inc.
b) IBM
c) Microsoft Corporation
d) Google

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Which type of Media Access Control (MAC) does SDLC utilize? a) Random access MAC b) Controlled access MAC c) Carrier Sense Multiple Access/Collision Detection (CSMA/CD) d) Time Division Multiple Access (TDMA)

If you use a 3270 protocol, you're using SDLC." This statement is: a) True b) False

What marks the beginning and end of a typical SDLC frame? a) Start and stop bits b) Special bit pattern known as the flag (01111110) c) Synchronization characters d) Header and footer fields

What is the typical length of the address field in an SDLC frame? a) 16 bits b) 8 bits c) 32 bits d) 64 bits

B.The address field identifies the destination. The length of the address field is usually 8 bits but can be set at 16 bits

What is the purpose of the control field in an SDLC frame? a) Identifying the destination address b) Indicating the beginning and end of the frame c) Specifying the frame type being transmitted d) Verifying the integrity of the message field

C. The control field identified frame type being transmitted: Information frames: For transferring of user message Supervisory frames: for acknowledgments (ACKs) and negative acknowledgments (NAKs).

What type of frames are used in SDLC for acknowledgments and negative acknowledgments? a) Information frames b) Error frames c) Supervisory frames d) Control frames

What is the primary purpose of acknowledgments (ACKs) and negative acknowledgments (NAKs) in SDLC? a) Encrypting the user's message b) Indicating the start and end of a frame c) Error correction and retransmission d) Specifying the destination address

What type of frames are used in SDLC for transferring user messages? a) Control frames b) Supervisory frames c) Information frames d) Error frames

What type of information is typically contained in the message field of an SDLC frame? a) Routing information b) Synchronization data c) The user's message d) Error detection codes

C. Variable in lengths

What does the frame check sequence field in an SDLC frame contain? a) Address of the sender b) User's message c) 32-bit CRC code d) Start and stop bits

C. (some older versions use a 16-bit CRC).

HDLC is very similar to the SDLC synchronous data link protocol.

________ has essentially replaced SDLC. It offers a larger sliding window. a. Ethernet b. PPP c. Asynchronous transmission d. HDLC e. Full complex

Which organization developed HDLC (High-Level Data Link Control) as a formal standard? a) IBM b) IEEE c) ISO d) IETF

What type of Media Access Control (MAC) does HDLC utilize? a) Random access MAC b) Controlled access MAC c) Carrier Sense Multiple Access/Collision Detection (CSMA/CD) d) Time Division Multiple Access (TDMA)

How does HDLC differ from SDLC in terms of address and control fields? a) HDLC has shorter address and control fields b) HDLC has longer address and control fields c) HDLC does not use address and control fields d) HDLC and SDLC have identical address and control fields

What characteristic of HDLC distinguishes it from SDLC in terms of Automatic Repeat Request (ARQ)? a) Smaller sliding window size b) Larger sliding window size c) Absence of sliding window size d) Identical sliding window size

In which type of network is LAP-B (Link Access Protocol–Balanced) commonly used? a) Local Area Network (LAN) b) Wide Area Network (WAN) c) Metropolitan Area Network (MAN) d) Personal Area Network (PAN)

How does LAP-B differ from HDLC? a) LAP-B is more complex than HDLC b) LAP-B offers fewer benefits than HDLC c) LAP-B has longer address fields than HDLC d) LAP-B has a smaller sliding window size than HDLC

In what situations is LAP-B often used? a) When full capabilities of HDLC are not needed c) When high-speed data transmission is required d) When extensive error correction is needed

What is the primary advantage of using cHDLC (Cisco HDLC) over standard HDLC? a) Increased complexity b) Additional field for specifying network protocol c) Smaller frame size d) Reduced data transmission speed

What purpose does the additional field in cHDLC serve? a) To specify the source address b) To specify the destination address c) To specify the network protocol being used d) To indicate the frame type

Contention is commonly used with Ethernet local area networks

Wired Ethernet is standardized as IEEE802.11.

802.3ac

The physical and data link layers of wired Ethernet have been refined over the years as a collection of standards under the IEEE 802.3 workgroup

The data link protocol, Ethernet (IEEE 802.3) is not very popular

Who is credited with the initial development of Ethernet? a) Alan Turing b) Bob Metcalfe c) Vint Cerf d) Tim Berners-Lee

When was Ethernet developed? a) 1960s b) 1973 c) 1985 d) 1990s

What media access protocol does Ethernet utilize? a) Controlled access b) Contention c) Token passing d) Time-division multiplexing

How many standard versions of Ethernet are there? a) Three b) Two c) Four d) Five

. The data link protocol, Ethernet (IEEE 802.3) uses parity bits for error detection.

The data link protocol, Ethernet (IEEE 802.3) is a bit-oriented protocol

F. Frame-oriented protocol

The data link protocol, Ethernet (IEEE 802.3) uses block check characters for error detection

F. frame check sequence for error detection

What marks the start of an Ethernet frame? a) Destination address b) Preamble c) Length field d) VLAN tag field

What is the purpose of the preamble in an Ethernet frame? a) To indicate the length of the message b) To mark the start of the frame c) To specify the source address d) To provide a repeating pattern of ones and zeros

Which field in the Ethernet frame specifies the receiver? a) Source address b) Length c) DSAP d) Destination address

When is the VLAN tag field used in an Ethernet frame? a) Always b) Only when the frame contains IPX/SPX protocol c) Only when VLANs are in use d) Only when the frame is of maximum length

How does Ethernet determine whether VLAN tags are in use in a frame? a) By checking the DSAP field b) By examining the CRC-32 frame check sequence c) By analyzing the length field d) By examining the value in the VLAN tag field

What information does the control field in an Ethernet frame hold? a) Frame sequence numbers and ACKs b) Destination address c) Length of the message d) Type of network layer protocol

How long is the VLAN tag field in an Ethernet 802.3ac frame? a) 4 bytes b) 6 bytes c) 8 bytes d) 10 bytes

What is the purpose of DSAP and SSAP fields in Ethernet frames? a) To specify the VLAN ID b) To indicate the frame's length c) To pass control information between sender and receiver d) To specify the source and destination addresses

What type of information does the control field in Ethernet frames hold? a) Source and destination addresses b) Frame sequence numbers and ACKs c) VLAN tag information d) Message payload

How are the last 2 bits in the first byte of the control field used? a) To indicate the VLAN ID b) To specify the length of the message c) To indicate the type of control information and the length of the control field d) To mark the end of the frame

In Ethernet frames, what is the typical length of the control field? a) 4 bytes b) 2 bytes c) 1 byte d) 8 bytes

What is the maximum message length in Ethernet frames? a) About 500 bytes b) About 1000 bytes c) About 1500 bytes d) About 2000 bytes

What is the purpose of the CRC-32 frame check sequence in Ethernet frames? a) To specify the source and destination addresses b) To hold frame sequence numbers and ACKs c) To mark the start of the frame d) To detect errors in the frame

How does Ethernet II mark the start of a frame? a) With a start of frame delimiter b) With a preamble c) With a VLAN tag field d) With a frame check sequence

What field in Ethernet II specifies the type of network layer packet the frame contains? a) Source address b) Destination address c) Type field d) Frame check sequence

What is the purpose of the type field in Ethernet II frames? a) To indicate the source address b) To specify the destination address c) To specify the type of network layer packet d) To indicate the VLAN ID

C. to specify an ACK frame or the type of network layer packet the frame contains (e.g., IP).

How does Ethernet II mark the end of a frame? a) With a special end-of-frame delimiter b) By sending a specific bit sequence c) By transmitting a pause signal for 96 bits d) By using a CRC-32 frame check sequenc

What is the purpose of the 96-bit pause at the end of an Ethernet II frame? a) To indicate the start of the next frame b) To provide a time buffer for error correction c) To prevent any one computer from monopolizing the circuit d) To synchronize with other network devices

What happens after the sending computer transmits no signal for 96 bits? a) The next frame starts immediately b) The sending computer waits for acknowledgment from the receiver c) The sending computer transmits the next frame, starting with a preamble d) The sending computer switches to a different transmission protocol

Which of the following is true about the data link protocol, Ethernet (IEEE 802.3)? a. It is not very popular. b. It is a bit-oriented protocol. c. it uses block check characters for error detection. d. Newer version permits jumbo frames. e. It uses parity bits for error detection

Which of the following is true about the data link protocol, PPP? a. it is commonly used in WANs b. it is a bit-oriented protocol c. it uses block check characters for error detection d. it was developed in the 1970s e. it uses parity bits for error detection

Media access control is not very important in point-to-point with full duplex configuration.

T. transfer date on point-to-point circuit

Media access control is not very important in a point-to-point with a half-duplex configuration.

Media access control: a. is not very important in point-to-point with full duplex configuration. b. is not very important in local area networks. c. is not very important in a point-to-point with a half-duplex configuration. d. is not very important in a multipoint configuration. e. does not control when computers transmit.

In which type of network is the Point-to-Point Protocol (PPP) commonly used? a) Local Area Networks (LANs) b) Wide Area Networks (WANs) c) Metropolitan Area Networks (MANs) d) Home Area Networks (HANs)

What type of protocol is Point-to-Point Protocol (PPP)? a) Bit-oriented b) Byte-count-oriented c) Frame-oriented d) Packet-switched

What is the primary purpose of the Point-to-Point Protocol (PPP)? a) To transfer data over multipoint circuits b) To establish connections in LANs c) To provide security in networks d) To transfer data on point-to-point circuits

How does the address field in PPP frames contribute to its versatility? a) It specifies the destination address in point-to-point setups b) It indicates the frame's length c) It allows PPP to be used on multipoint circuits d) It determines the type of data packet carried

What is typically included in the PPP frame to mark its beginning? a) Address field b) Control field c) Protocol field d) Flag

How long is the address field in PPP frames? a) 2 bytes b) 4 bytes c) 6 bytes d) 1 byte

D. Unused address field

What does the protocol field in PPP frames indicate? a) The type of network medium being used b) The physical address of the sender c) The type of data packet carried (e.g., an IP packet) d) The encryption algorithm used for data transmission

What is the maximum length of the data field in PPP frames? a) 1000 bytes b) 2000 bytes c) 1500 bytes d) 500 bytes

What type of frame check sequence is typically used in PPP frames? a) CRC-8 b) CRC-16 c) CRC-32 d) Checksum

B,C

What is the purpose of the control field in PPP frames? a) To specify the source and destination addresses b) To provide error correction capabilities c) To determine the type of data packet carried d) It is typically unused.

What is the primary objective of network transmission efficiency? a) To maximize errors b) To minimize the volume of bits c) To move as many bits as possible with minimum errors d) To increase costs

Which factor contributes to higher network efficiency and lower cost? a) Higher error rate b) Lower data rate c) Higher volume of bits d) Slower processing speed

Which of the following is NOT a factor affecting network efficiency? a) Circuit's error rate b) Circuit's data rate c) Size of the transmission medium d) Error-detection and control methodology

Overhead bits are used for error checking and marking the start and end of characters and packets.

. Transmission efficiency refers to the percentage of bits transmitted without errors

_________________ is defined as the total number of information bits divided by the total number of bits in the transmission. a. Asynchronous rate b. Protocol percentage c. Throughput d. Transmission Rate of Information Bits e. Transmission efficiency

. Calculating the actual throughput of a data communication network is: a. not normally required for synchronous networks because they are so fast b. complex because many factors affect throughput c. simple because packet size is the primary factor affecting throughput d. not needed for satellite-based networks e. far less complicated if the system operates on a contention basis

What is the relationship between message length and efficiency in data transmission? a) Larger message length results in lower efficiency b) Larger message length results in higher efficiency c) Message length does not affect efficiency d) Efficiency is independent of message length

chapter 4 (2) Flashcards

(100 cards)