4.9: section 10: the internet Flashcards
what is the internet
a network of interconnected computer networks which use end to end communication protocol
what is the world wide web
a collection of web pages residing on computers connected to the internet
how is the internet physically structured
each continent uses back bone cables connected by trans continental leased lines
how do national internet service providers provide an internet connection
they connect directly to the back bone cables and distribute internet connection yo smaller providers who provide access to individual homes and businesses
what are URLs
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
why are internet registrars necessary
they are needed to ensure that domain names are only used once
what are internet registries
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
what are internet registries for
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
what is a domain name
how the area or domain an internet resource resides in is identified
what is the domain name system
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
what is an (IP) internet protocol address
a unique address which is given to a single network device. It performs a similar function to your home address-typically strings or numbers
what makes up the abstract internet
massive collections of domain names, servers and routers that tell computers where to go to find web resources
Packets routed across various routes
what does a router do
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
what makes a gateway different from a router
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
what is a packet
bundle of data sent out across the internet to a destination. It is wrapped in other data which tells it the source and destination
what information is included in packets
HEADER:
Destination and source IP address
Destination and source mac address
Packet sequence numbers
PAYLOAD: Data
TRAILER: Checksum
define packet switching
Method or protocol used to send multiple packets out across the internet
what 7 steps go into packet switching
RSCNATS
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
what is a (FQDN) fully qualified domain name
a part of the URL including the host server name, website, company 2LD and country TLD
host+ website domain name= FDQN
define client thickness
the amount of processing and storage a computer does in comparison to the server its connected to
define thick clients
the majority of processing and storage is done on the client computer
what are the advantages of thick clients
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
what are the disadvantages of thick clients
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
define thin clients
the majority of processing and storage is done on the server. The pcs are called dumb terminals
what are the advantages of thin clients
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
what are the disadvantages of thin clients
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
