3.1.13 Networking

Question 1

what is a computer network?

Answer 1

2 or more computers connected together through a communication medium to form a network

Question 2

what is the purpose of a network (connecting computers together) ? {2}

Answer 2

• to exchange information and data

- use the resources of other computers on the network

Question 3

Advantages of computer networks {9}

Answer 3

• allows users to share software stored in a main system
• site (network) software licenses are less expensive than buying several standalone licenses
• files can be easily shared between users over a network
• network users can communicate via email, instant messenger and VoIP
• security over networks is of high standard
• much more straightforward to back up data as it is stored on a file server
• allows data to be transmitted to remote areas that are connected within local areas
• allows users to share common peripheral resources (saves money)
• cost of computing is reduced per user

Question 4

Disadvantages of computer networks {5}

Answer 4

• cabling to construct a network and file servers van be costly
• management of a large network is complicated (requires training and a specialist network manager needed)
• files on the server can become inaccessible if the file server breaks down
• a virus an easily spread throughout the network to other computers if it gets into the system
• risk of hacking (security measures e.g. firewalls required to prevent this)

Question 5

exam tip

Answer 5

you need to be able to discuss the advantages and disadvantages of using a computer network (press 5 to move on)

Question 6

NEW TOPIC: Basic components of a computer network

Answer 6

press 5 to move on

Question 7

what are servers?

Answer 7

powerful computers that provide services to other computers on the network

Question 8

what are clients?

Answer 8

computers that use the services that the server provides

Question 9

is a server or client LESS powerful?

Answer 9

clients are less powerful than the server

Question 10

what does a communication media consist of?

Answer 10

the physical connections between the devices on a network (e.g. wireless signal/ internet)

Question 11

what is a network adapter also referred to?

Answer 11

a netwrok interface card (NIC)

Question 12

what is a network adapter / NIC?

Answer 12

a circuit board equipped with the necessary components for sending and receiving data

usually plugged into one of the available slots on a computer and a transmission cable is attached to the connector on the NIC

Question 13

what is meant by resources?

{2}

Answer 13

any peripheral device that is available to a client on the network
also refers to data and information

Question 14

who is the user?

Answer 14

any person that uses a client to access resources on the network

Question 15

what are the protocols of a network?

Answer 15

rules used for the network communications

Question 16

NEW TOPIC: Network topologies

Answer 16

press 5 to continue

Question 17

what is a bus topology?

draw a sketch

Answer 17

acts as a shared communication medium that connects to devices via an interface connecter

https://nooradelima.files.wordpress.com/2014/11/bus.gif
^click this link to check answer for your sketch

Question 18

adv of bus topology {5}

Answer 18

• Easy and cheap to install
• Suitable for small networks
• Easy to add extra workstations
• Uses less cable than a Star network
• Best choice for temporary networks

Question 19

disadv of bus topology {4}

Answer 19

• Cable length is limited (restricts number of devices that can be connected to the network)
• As more devices are connected, the performance of the network slows down (due to data collisions)
• If there is a problem with the central cable, the entire network stops working
• Low security - every workstation can see all of the data in the network

Question 20

what is a ring topology?

draw a sketch

Answer 20

data passes from one computer to the next one all the way around the ring until it reaches the destination computer.

http://www.teach-ict.com/images/network_ring.jpg
^click this link to check answer for your sketch

Question 21

adv of ring topology {5}

Answer 21

• central server not required
• messages sent between 2 workstations pass through all the intermediate devices
• Transmission of data is fairly simple as it only travels in one direction
• No data collisions
• Extra computers can be added easily with little effect on performance - although you have to shut down the network to do this.

Question 22

disadv of ring topology {2}

Answer 22

• failure of any cable within the network can cause network to crash
• alterations to any device within the network can affect performance of the whole network

Question 23

what is a star topology?

draw a sketch

Answer 23

each workstation is connected by its own cable directly to the server.

http://www.teach-ict.com/gcse_new/networks/topologies/miniweb/pg4.htm
^click this link to check answer for your sketch

Question 24

adv of star topology {5}

Answer 24

• Star networks are very reliable. If one connection fails, it does not affect other users
• Very few data collisions as each workstation has its own cable to the server
• Good security - no workstation can interact with another without going through the server first

Question 25

disadv of star topology {4}

Answer 25

• The most expensive network layout to install because of the amount of cables needed
• Installing the network usually needs experts to set it up
• Extra hardware such as hubs and switches may be needed
• If the server crashes then nobody will be able to use the network.

Question 26

the number of bits that can be transmitted over a network I’m a certain period of time is:

Answer 26

bandwidth

Question 27

a technique in which stem resources are shared among multiple users is:

Answer 27

multiplexing

Question 28

3.1.13.1 Client-server

Answer 28

press 5 to continue

Question 29

what is the client-server model?

Answer 29

a structure that splits tasks between servers and clients

Question 30

what is a server?

Answer 30

they provide a service to the clients

Question 31

what is a client?

Answer 31

they use the services provided by the server

Question 32

what is a protocol?

Answer 32

a set of rules that control the transfer of data between computers

Question 33

why are protocols essential? {3}

Answer 33

they determine the:

• speed of transmission
• size of bytes
• error checking methods

Question 34

what is Handshaking?

don’t describe the process just yet

Answer 34

two computers exchange signals in order to set up a communication link.

Question 35

explain what happens during Handshaking?

when 2 computers connect

Answer 35

• establishes what protocols to use and controls the flow of data between the computers
• protocol parameters are negotiated
• handshaking protocols must be completed before finishing the action requested by the user

Question 36

how would a typical Handshaking process go?

Answer 36

1. a request to connect is sent
2. a connection is granted
3. protocol parameters agreed

Question 37

what is client-side programming?

Answer 37

writing code that will run on the client, done in languages that can be executed by the browser

Question 38

what is server-side programming?

Answer 38

writing code that runs on the server e.g. PHP

Question 39

check your understanding:

what are the 5 basic needs of a networked communication system?

Answer 39

• data source
• transmitter
• transmission medium
• receiver
• destination (where data will be placed)

Question 40

Advantages of client server applications over web-based applications.

Answer 40

• You are in control of upgrades.
• You have to manage your own systems and pay for technical support.
• Applications tend to run faster when they are local to the user’s computer.