Data Communication Lesson 1

Questions and Answers

What is the approximate diameter of a campus network?

1 ~ 10 meters

1 ~ 10 kilometers (correct)

10m - 200m

1 ~ 5 meters

Which of the following is NOT considered a component of the Internet's 'edge'?

end systems

network apps

hosts

routers (correct)

Which type of network connection is typically used for devices connecting directly to each other via Wi-Fi without an access point?

Wired LAN

Bluetooth

Cellular network

Ad-hoc Wi-Fi (correct)

What is the primary function of packet switches in the Internet?

To forward packets of data Signup and view all the answers

Which of the following is an example of a device that is typically connected to a PAN?

A smartphone connected to a headset Signup and view all the answers

What is the difference between an intranet and an extranet?

An intranet is for internal use, while an extranet is for external use with controlled access. Signup and view all the answers

What is the primary function of a content provider network in the Internet?

To deliver content, such as web pages and videos, to users Signup and view all the answers

Which of the following is NOT considered a type of network extent?

Regional area network (RAN) Signup and view all the answers

What is the approximate diameter of a local area network (LAN)?

10m - 200m Signup and view all the answers

What is the meaning of 'bandwidth' in the context of communication links?

The maximum amount of data that can be transmitted per unit of time Signup and view all the answers

Which of the following best describes the concept of 'Data Communication' as discussed in the text?

The exchange of information between two or more entities, where the information is represented as data, often in digital format. Signup and view all the answers

Based on the text, what is the key difference between 'Analog' and 'Digital' data?

Analog data is continuous, while digital data is discrete and represented using 1s and 0s. Signup and view all the answers

Which of the following is NOT a component of a data communication system, as described in the text?

Channel Signup and view all the answers

What is the significance of the 'Protocol' component in a data communication system?

Protocol defines the rules and formats for communication, ensuring that both sender and receiver understand the data. Signup and view all the answers

Which of the following is an example of 'Analog data' as discussed in the text?

The temperature of a room Signup and view all the answers

Based on the text, which of the following is a key advantage of using digital data in communication?

Digital data is less susceptible to noise and distortion during transmission. Signup and view all the answers

Which of the following examples is NOT mentioned in the text as a type of data that can be communicated?

Software Signup and view all the answers

What does the text suggest is the primary focus of data communication in today's world?

Communication using digital signals. Signup and view all the answers

Which statement is true regarding the bus topology?

Signal absorption at the terminators is essential for proper communication. Signup and view all the answers

What is a key characteristic of a ring topology?

Signals pass from device to device in a single direction only. Signup and view all the answers

In a star topology, what is the role of the hub?

To act as a relay and exchange data between devices. Signup and view all the answers

Which statement accurately describes tree topology?

It has a hierarchical structure with multiple levels of interconnected devices. Signup and view all the answers

What distinguishes full-mesh connectivity from other topologies?

Every device connects to all other devices. Signup and view all the answers

Which of the following best describes multicast data flow?

Data is specifically sent to a selected group of nodes that subscribe. Signup and view all the answers

Which statement about circuit switching is NOT true?

It allows for efficient connections with minimal delays. Signup and view all the answers

What is a disadvantage of using a full-mesh topology?

It can require an impractical number of links as network size increases. Signup and view all the answers

In circuit switching, which phase occurs directly after the connection establishment?

Data transfer Signup and view all the answers

What happens when the arrival rate of packets exceeds the output link capacity?

Packet loss occurs due to a full buffer. Signup and view all the answers

How is 'throughput' defined in a data communication context?

The rate of successfully sent bits from sender to receiver. Signup and view all the answers

What is a potential consequence of packets arriving at a full buffer?

Packets may be lost. Signup and view all the answers

What type of delay occurs when packets are queued in a buffer?

Queueing delay Signup and view all the answers

In a network data transmission, what can happen if the queue preceding a link reaches its maximum capacity?

Newly arriving packets are dropped. Signup and view all the answers

What characterizes the 'instantaneous throughput' in data communication?

The data rate at a specific moment in time. Signup and view all the answers

Which statement about packet loss is accurate?

Packet loss may happen if there is no available buffer to store packets. Signup and view all the answers

Which factor primarily determines the length of time packets spend in a queue?

The arrival rate of packets compared to the output link capacity. Signup and view all the answers

What is one characteristic of a metropolitan area network (MAN)?

Its diameter ranges from 10 to 50 kilometers. Signup and view all the answers

Which network topology involves all stations connecting to a common linear medium?

Bus Signup and view all the answers

Which statement correctly describes the point-to-point connection?

It provides a dedicated link with reserved capacity for two devices. Signup and view all the answers

What is a common feature of a wide area network (WAN)?

It can span a distance of 10 km to over 1000 km. Signup and view all the answers

What distinguishes tree topology from other topologies?

It combines characteristics of star and bus topologies with hierarchical structure. Signup and view all the answers

Which topology allows for multiple paths between devices for data transmission?

Mesh Signup and view all the answers

Study Notes

What is Data Communication?

Data communication is the process of exchanging or sharing information or messages between communicating entities, which can be human-to-human or non-human (devices or systems).
Data communication involves representing information or messages as "data", which can be analog or digital.
Analog data is continuously varying in time and amplitude, while digital data is represented using 1s and 0s.

Components of Data Communication Systems

The five components of a data communication system are:
Message: the information (data) to be communicated.
Sender: the device that sends the data message.
Receiver: the device that receives the data message.
Transmission medium: the channel through which the data message is sent.
Protocol(s): the set of rules governing data communication.

Message

The message can be of various types, including text, numbers, image, video, and audio.
Each type of message has its own representation, such as text being represented using ASCII codes.

Sender

The sender is the device that sends the data message, which can be a computer, gaming devices, or internet phones.

Networks

A network is a collection of interconnected devices, routers, and links, managed by an organization.
Networks can be classified based on their extent, including:
Personal Area Network (PAN)
Local Area Network (LAN)
Campus Network
Metropolitan Area Network (MAN)
Wide Area Network (WAN)
Intranet/Extranet/Internet

Network Topologies

Network topologies include:
Point-to-point: a dedicated link between two devices.
Bus: all stations attach directly to a linear transmission medium.
Ring: each device has a dedicated point-to-point connection with only the two devices on either side.
Star (hub and spoke): each device has a dedicated point-to-point link only to a central controller.
Tree: multiple levels of star-type networks.
Mesh: devices have dedicated point-to-point links to one or many other devices.

Data Flow in Networks

Data flow can be classified into three types:
Unicast: from the sender to one destination node.
Broadcast: from the sender to all destinations (nodes) in the network.
Multicast: from the sender to selected destinations.

Circuit Switching

Circuit switching uses a dedicated path between two stations.
It has three phases: connection establishment, data transfer, and disconnection.
It can be inefficient, as channel capacity is dedicated for the duration of the connection, even if no data is being sent.

Packet Switching

Packet switching does not allocate end-end resources, and packets queue in router buffers, waiting for their turn for transmission.
Packet loss occurs when memory to hold queued packets fills up, and packets are dropped.

Performance Metrics

Packet loss: the percentage of packets that are lost during transmission.
Delay: the time taken for a packet to travel from the sender to the receiver.
Throughput: the rate at which bits are being sent from the sender to the receiver.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the basics of data communication, including types of data, components of a data communication system, message types, and network topologies. It also touches on circuit switching, packet switching, and network performance.