Introduction to Networks

Question 1

Define a network

Answer 1

Two or more connected computers that can share access to resources

Question 2

Define a LAN

Answer 2

A local area network spans a small geographic area such as a home or office building

Question 3

Define a workstation

Answer 3

A powerful computer running multiple CPUs whose resources are available to other users on the network to access

Question 4

Define a server

Answer 4

A powerful computer that runs specialised software (the network OS) to maintain/control the network

Question 5

Define a host

Answer 5

Any network device with an IP address

Question 6

Define a WAN

Answer 6

A wide area network spans a large geographic area and employs both routers and public links

Question 7

Name 4 ways WANs differ from LANs

Answer 7

1. WANs usually need a router port/s
2. WANs span a larger area and can link separate locations
3. WANs are slower
4. We can choose when/how long we connect to w WAN, but not with a LAN

Question 8

What is MPLS?

Answer 8

Multiprotocol Label Switching (MPLS) is a switching mechanism that imposes labels to data and uses them to forward data when it arrives at an MPLS network

Question 9

What is a peer-to-peer network?

Answer 9

Hosts connect directly to other hosts with equal authority; there is no central authority in a P2P network

Question 10

What is a client-server network?

Answer 10

Where a single server uses a network OS to manage a whole network; clients request resources from the main server, which handles security and directs clients to resources

Question 11

What is the OSI model?

Answer 11

The Open Systems Interconnections model describes how data and network information are communicated from an application on one computer through network media to an application on another computer. It has 7 layers: Application, Presentation, Session, Transport, Network, Data Link, and Physical.

Question 12

Describe the Application Layer of the OSI model

Answer 12

The Application layer is layer 7 of the OSI model. It performs file, print, message, database, and application services and a user interface

Question 13

Describe the Presentation Layer of the OSI model

Answer 13

The Presentation layer is layer 6 of the OSI model. It provides data encryption, compression, and translation services, presents data, and handles encryption

Question 14

Describe the Session Layer of the OSI model

Answer 14

The Session layer is layer 5 of the OSI model. It provides dialog control and keeps different applications’ data separate

Question 15

Describe the Transport Layer of the OSI model

Answer 15

The Transport layer is layer 4 of the OSI model. It provides an end-to-end connection, reliable or unreliable delivery, and performs error connection before retransmitting data

Question 16

Describe the Network Layer of the OSI model

Answer 16

The Network layer is layer 3 of the OSI model. It provides routing and logical (IP) addressing

Question 17

Describe the Data Link Layer of the OSI model

Answer 17

The Data Link layer is layer 2 of the OSI model. It combines packets into bytes and bytes into frames, provides access to media using MAC addresses, and performs error detection

Question 18

Describe the Physical Layer of the OSI model

Answer 18

The Physical layer is layer 1 of the OSI model. It describes the physical topology, moves bits between devices, and specifies voltage, wire speed, and pin-out of cables

Question 19

At what layer is data segmented into a data stream?

Answer 19

The Transport layer (layer 4)

Question 20

At what layer do TCP and UDP operate?

Answer 20

The Transport layer (layer 4)

Question 21

At what layer do routers work?

Answer 21

The Network layer (layer 3)

Question 22

At what layer do switches work?

Answer 22

The Data Link layer (layer 2), or the Network layer for Layer 3 switches

Question 23

True or false: broadcasts are forwarded through routers

Answer 23

False. Broadcasts aren’t forwarded through a router. Routers break up broadcast domains.

Question 24

What is a PDU?

Answer 24

A Protocol Data Unit holds control information attached to data at each layer of the OSI model

Question 25

Describe the 5-steps of data encapsulation

Answer 25

1. Data
2. Segments
3. Packets (datagrams)
4. Frames
5. Bits

Question 26

Define modulation

Answer 26

Modulation is the process of taking an analog signal and converting it into a digital signal, or vice versa

Question 27

What are the Data Link layer sublayers?

Answer 27

The LLC sublayer and the MAC sublayer

Question 28

At what layer do hubs and repeaters operate?

Answer 28

At the Physical layer (layer 1); hubs and repeaters only see bits

Question 29

At what layer do switches and bridges operate?

Answer 29

At the Data Link layer (layer 2). Switches and bridges make decisions based on MAC addresses.

Question 30

At what layer do routers operate?

Answer 30

At the Network layer (layer 3). Routers make decisions based on IP addresses.