The Internet Flashcards
What is the internet ?
Network of interconnected computers that use an end to end communication protocol
Protocal?
Set of rules that allows for communication of devices
Internet service providers?
Company that provides customers with internet , and national service providers provide internet for national companies
What is a packet and what is included inside them?
Bundle of data which is transmitted over a network.
They contain an address for the sender and recipient and inside the packet it contain information intended for the recipient.
How does packet switching work?
Data is sent in packets.
Data is split into smaller packets each of which is sent to the recipient via the best route.
Reassembled with other packets by its recipient.
What happens when a packet sent through a network?
Packets are said to take a number of routes before reaching its destination.
What is the role of the router in packet switching?
Uses the packets address to determine where to send the packet, each time a packet passes a router it said that a hop occurs.
What is a packets time to live?
Packets have a finite hops , so TTL is a number that indicates how many hops the packet can have and each time it hops it minus the hop value by one.
What happens when TTL expires?
The packet is dropped (deleted) , the recipient (receiver) will notice the missing packet and will request for sender to send the missing packet.
Senders address?
Identifies where packet was sent from ; and where it should be sent to.
Receivers address?
Shows the packets intended recipient and this allows it to be forwarded TO THE CORRECT DEVICE.
SEQUENCE NUMBER?
Contains no. Of packets in a message and shows the position in relation to others.
Also reassembles packets in correct order and allows missing packets to be identified.
Purpose of routers and gateways?
Connect different networks and allow packets to reach their destination.
What is the main function of routers(ADS)
They send packets to destination via the shortest route possible whether it is the least no. Of hops or the least congested path.
Role of gateways?
Strip away most of packets details and leaving with just the packets contents.
Gateways gives a new sender and receiver addresses.
What is uniform resource locators?
Address assigned to files on the internet.
HTTPS:// ?
Hypertext transfer protocol secure .
Protocol being used to a access file.
Www ?
World Wide Web
Points to the server hosted at the following domain.
BBC.co.uk ?
Domain.
BBC is the name of the organisation
.uk is a top level domain
.co is a second level domain.
/news ?
Directory of file being requested
What are domain names?
Identifies an organisation or an individual on the internet.
FDQN?
FULLY QUALIFIED DOMAIN NAME
Will always include the servers host name and specifies the exact resource and is interpreted only in one way.
Vaguely explain how IP addresses are incorporated in the internet?
They assigned to every computer on the internet.
The are basically the exact same as domain names only that IP addresses are not user friendly.
What ARE DNS used for?
Translates the domain name into its corresponding IP address.
What happens if DNS does not have a record of the domain
Request will be passed to another domain name server. That y some unknown apps are slower than large websites
What is the purpose of a domain name server on the internet?
To translate domain names into IP addresses.
2 roles of routers
Manage congestion Route packets according to destruction IP address. ‘
What is packet switching
Messenger sprit into packets, where each packet is given a source + destination address.
Why must the port no. Be well known?
Clients must know which port no. To connect to. Communication initiated by cells
What is the purpose of a gateway
To connect network using different protocols
explain why browsing the internet might be slower at a public hotspot in a coffee shop than at home on a wireless network.
In coffee shop there are may be more collisions .
In coffee shop there may be collisions.
