Computer Communications and Networking

Question 1

What are the advantages of networking stand-alone computers into a LAN?

Answer 1

sharing resources (internet connection, peripherals, files) communication, centralized management

Question 2

What hardware is needed to connect stand-alone computers to a LAN?

Answer 2

hub/switches, wireless access points, wires

Question 3

What are the roles of computers in a client-server network?

Answer 3

A main server can be a: database, file, mail, web, gaming server and provides quick, reliable access to computers that need it
server provides services to many client machines

Question 4

What are the roles of computers in a peer-to-peer network?

Answer 4

all computers are equal and serve needs for the user as well as carrying out networking
maintenance is more difficult than client-server, poor security, slower

Question 5

What is the bus network topology?

Answer 5

devices are attached along a single backbone
easy to set up, cheap
problems with backbone brings down whole network, hard to isolate a problem, many data collisions slowing down network

Question 6

What is the ring network topology?

Answer 6

devices are attached in a ring
not dependent on a central computer, token passing protocol is simple and reliable, fast performance as one way so no collisions
problems with backbone brings down whole network, data passes through every device

Question 7

What is the star network topology?

Answer 7

all devices connect to one central hub/switch/computer
few data collisions, if one cable fails only one affected, easy to add new computers
costly, dependence on central computer

Question 8

What are the differences between a LAN and a WAN?

Answer 8

Local/Wide area network, WAN is over separate locations by going through a service provider

Question 9

What is IP addressing?

Answer 9

A numerical label that identifies each computer using internet protocol to communicate over a wide network
DNS connects IP address to user-friendly names

Question 10

What is MAC addressing?

Answer 10

Every networked device will have a MAC address on the NIC when manufactured
It is a 48-bit address and is used to transmit devices with LAN

Question 11

What is a packet?

Answer 11

When devices communicate with each other the messages are broken into smaller parts called packets which are broadcast onto the LAN with the MAC address of the destination

Question 12

What are protocols?

Answer 12

A set of rules that define how devices communicate.
It covers: how communication will start, the transmission speed, how the bits are delivered (one at a time), error checking etc.

Question 13

What is the need for security measures in networks?

Answer 13

user access levels, suitable passwords, encryption techniques

Question 14

What is the network policy - acceptable use?

Answer 14

restriction on transmitting (e.g. obscene material), not using the network for bulk mailing/marketing, not wasting staff time, not corrupting/destroying data, not violating privacy, not installing unauthorized software

Question 15

What is the network policy - disaster recovery?

Answer 15

A plan that covers what to do in the event of catastrophic data loss
it covers: prevention, backups, who will be involved in recovery, how to recover data, how long it should take

Question 16

What is the network policy - failover?

Answer 16

When the software detects a potential disaster or abnormality it immediately transfers operations to a duplicate system

Question 17

What is the network policy - back up?

Answer 17

To protect against data loss, important data is copied to a secure storage option (cloud)
Backups should be done often enough so if there is a data loss incident, all important files should be safe

Question 18

What is the network policy - archiving?

Answer 18

Old, no longer in use data is kept in case future enquiries need it or for legal reasons

Question 19

What is the internet?

Answer 19

worldwide collection of computer networks

Question 20

What is the hardware needed to connect to the internet?

Answer 20

modems converts digital-analogue but is very slow and not used nowadays
Routers can be connected to the internet via fibre optic cable, or part of the telephone line, your computer connects to the router to get an internet connection

Question 21

What is the need for IP addressing of resources on the internet and how this can be facilitated by the role of DNS services?

Answer 21

websites are stored on web servers connect to the internet, and each site has a unique IP address. When you type a domain name ‘www.bbc.co.uk’, the request is sent to a DNS server, which translate the domain name into the IP address, if the local DNS server does not have the name listed it forwards the request to another
The advantages of a DNS server to translate domain names: humans don’t have to remember IP addresses, if the IP address changes the DNS servers update with the same domain name

Question 22

What is the importance of HTML and its derivatives as a standard for the creation of web pages?

Answer 22

Hyper Text Markup Language is used to describe the page content
it is important to be a standard so everyone can access it

Question 23

What are common file standards associated with the internet?

Answer 23

JPG (image), GIF (bitmap image), PDF (documents), MP3 (audio), MPEG (video), AVI (video)

Question 24

Why do you need to compress files that are transmitted via the internet?

Answer 24

As smaller files take less time to transmit over the network, it would take to long to view files/sites etc.

Question 25

What is the difference between lossy and lossless compression?

Answer 25

lossy - where data compression involves remove some detail/data, mainly for multimedia files
lossless - no data is lost when compressed, for bank statements, source code etc