INTERNET AND DATA TRANSMISSION

Question 1

What is a network

Answer 1

Collections of computing devices, called nodes

Question 2

What are NICs

Answer 2

Network interface cards are what receive and transmit signals

Question 3

What is a MAC address

Answer 3

48 bit idenfiers for network devices, contains the manufacturer number

Question 4

What is a router

Answer 4

A device which connects networks, for example connecting you to your ISP from LAN

Question 5

What is a WAP ;)

Answer 5

What wireless devices connect to.

Question 6

3 types of network topologies

Answer 6

BUS STAR RING

Question 7

Bus vs star vs ring topology

Answer 7

Bus is every node connects to a single cable
Star is there is a central node and everything else connects to it, a hub is in the middle
Ring is where all nodes are connected cyclically

Question 8

LAN vs WAN

Answer 8

lan is local to a geographical area

Wans cover a large geographical area,like internet

Question 9

Two types of network organisations

Answer 9

CLIENT SERVER

PEER TO PEER P2P

Question 10

3 layers to a network and what they area

Answer 10

APPLICATION - sets up the data to be received and sent
NETWORK - where the data gets sent to, and how to sent it there (through the topology etc)
PHYSICAL - physical sending of the data through fiber optic etc

Question 11

What is a protocol

Answer 11

Rules for how a network should communicate

Question 12

What are the four layers of abstraction in the TCP IP stack and what they are

Answer 12

Application - packing up the data and dealing with it, compressing too etc, client side
Transport - deals with the connection, reliable flow of data
Internet - deals with the IP and packing the data into the format (header + payload data)
Link - passes data grams to the LAN, physically

Question 13

What is a data gram

Answer 13

Entity of data which contains where it needs to go and other metadata

Question 14

What is circuit switching

Answer 14

When a direct route for the connection is established for the duration of a communication, you ‘rent’ the connection for a duration of time, can make long distance calls expensive

Question 15

What is packet switching

Answer 15

Where data is split into packets of data and assigned an id for its order. The data gets sent along any route available and is reassembled

Question 16

How do the levels of domains in a DNS hierarchy work

Answer 16

1st level is domains like .com, .uk, .edu
2nd level is domains like .co .org (eg .co.uk or .org.uk)
3rd level is domains like Instagram etc
There is a root domain at the top

Question 17

What is a brute force attack

Answer 17

Keeping on trying passwords until getting in

Question 18

What is a firewall

Answer 18

Packet filtering, controlling the traffic coming into a network

Question 19

What is a proxy server

Answer 19

A server which is between the user and and incoming packets. If it’s a banned thing, then it never gets to the users computer

Question 20

What is a scripting language

Answer 20

A language designed to run in a virtual environment and is not compiled down to object code.

Question 21

What can be added to a html document to include it in the search engine search algorithms

Answer 21

Meta tags, included in the part. Has tags such as keywords, content and author etc

Question 22

What is the dampening factor

Answer 22

The probability that a person searching is likely to continue

Question 23

Pagerank algorithm and its arts

Answer 23

for N linking pages
PR(A) = (1-d) + d( PR(TN)/C(TN) + …)
PR(x) is the page rank of page X, where it’s the number of pages that have a link to page x
C(x) is the number of links that are in page X that point elsewhere (outbound)
D is the dampening factor between 0 and 1

Question 24

Pros of client side processing

Answer 24

Reduces server load (because)
Data is checked client side
reduces web traffic by not sending erroneous data

Question 25

Pros of server side processing

Answer 25

Client side could not be valid
Validation of the data can be ensured (so)
it can stop unwanted data accesses (therefore)
making the connection and server system safe.

Question 26

3 lossy compressors

Answer 26

PJEG MP3 MPEG

Question 27

Symmetric vs assemetric encryption

Answer 27

Symmetric used the same key to encrypt and decrypt

Asymmetric uses a public key to encrypt data anywhere and a private key only to decrypt

Question 28

What is a password salt

Answer 28

Random data appended to password before hashed.

Salt is also stored the hash and used to decrypt (not checksum hash)

Question 29

What is a server

Answer 29

A device which provides a central point of access