4.9: section 10: the internet

Question 1

what is the internet

Answer 1

a network of interconnected computer networks which use end to end communication protocol

Question 2

what is the world wide web

Answer 2

a collection of web pages residing on computers connected to the internet

Question 3

how is the internet physically structured

Answer 3

each continent uses back bone cables connected by trans continental leased lines

Question 4

how do national internet service providers provide an internet connection

Answer 4

they connect directly to the back bone cables and distribute internet connection yo smaller providers who provide access to individual homes and businesses

Question 5

what are URLs

Answer 5

uniform resource locators are the full address of internet resources that specify the resource location on the internet so the browser can request it from the website server

Question 6

why are internet registrars necessary

Answer 6

they are needed to ensure that domain names are only used once

Question 7

what are internet registries

Answer 7

5 global organizations governed by the internet corporation for assigned names and numbers (ICANN)

North America: ARIN
South America: lacnic
Africa: AFRINIC
Asia/Pacific Islands/Australia: APNIC
Europe/Middle East: RIPE NCC

Question 8

what are internet registries for

Answer 8

they have a world wide data base listing all domain names in use in order

they allocate IP addresses and keep track of addresses associated with the domain name for the DNS

Question 9

what is a domain name

Answer 9

how the area or domain an internet resource resides in is identified

Question 10

what is the domain name system

Answer 10

an internationally agreed structure which classifies the area an an internet resource resides

Structured in hierarchy fashion

Small domains appear lower

When written you work up from the bottom using dots to separate

Question 11

what is an (IP) internet protocol address

Answer 11

a unique address which is given to a single network device. It performs a similar function to your home address-typically strings or numbers

Question 12

what makes up the abstract internet

Answer 12

massive collections of domain names, servers and routers that tell computers where to go to find web resources

Packets routed across various routes

Question 13

what does a router do

Answer 13

receive packets on a network and forwards them to the correct destination based on address

Intelligent device which uses a table and algorithm to decide the best route onwards

Wan be wired or wireless

Question 14

what makes a gateway different from a router

Answer 14

Able to forward packets travelling between devices with different protocols by…

1: strips header data from incoming packing leaving the raw data
2: adds new header in format needed for the destination network and sends the packet out

Question 15

what is a packet

Answer 15

bundle of data sent out across the internet to a destination. It is wrapped in other data which tells it the source and destination

Question 16

what information is included in packets

Answer 16

HEADER:
Destination and source IP address

Destination and source mac address

Packet sequence numbers

PAYLOAD: Data

TRAILER: Checksum

Question 17

define packet switching

Answer 17

Method or protocol used to send multiple packets out across the internet

Question 18

what 7 steps go into packet switching

RSCNATS

Answer 18

1: network interface card receives message to send out data
2: NIC splits the message up into equally sized packets and numbers them - a checksum is calculated and added to the packet
3: packets are routed to the local ISP - each is checked on arrival for corruption
4: packets are routed to the next node - depends on bandwidth, congestion, other factors-each packet may take its own route
5: packets arrive at the ISP of the destination computer
6: packets arrive at destination computer and TCP re-orders the packets into the correct sequence:
7: protocol bits are stripped from packet so the original data is passed to the application that needs it

Question 19

what is a (FQDN) fully qualified domain name

Answer 19

a part of the URL including the host server name, website, company 2LD and country TLD

host+ website domain name= FDQN

Question 20

define client thickness

Answer 20

the amount of processing and storage a computer does in comparison to the server its connected to

Question 21

define thick clients

Answer 21

the majority of processing and storage is done on the client computer

Question 22

what are the advantages of thick clients

Answer 22

More robust and reliable

Greater up time and services ability

Preferred to run heavy duty software

Pcs can be used without relying on a strong connection to the server

Question 23

what are the disadvantages of thick clients

Answer 23

More expensive as client pcs will need to have higher specifications

Every client will have the own software installed meaning updates will need to be downloaded individually increasing effort for the network administration team

As the network isn’t centralized integrity issues are increased

Question 24

define thin clients

Answer 24

the majority of processing and storage is done on the server. The pcs are called dumb terminals

Question 25

what are the advantages of thin clients

Answer 25

Software can be updated automatically to all clients via the server

Easier to add new terminals

Data is more secure as it is stored in a central place on the server

Question 26

what are the disadvantages of thin clients

Answer 26

Heavily reliant on the server. If the server goes down most functionality is lost

Dependent on a powerful and reliable central server which will be expensive

Method demands a higher bandwidth