OCR comp - internet communication

what is circuit switching?

• a drirect link is created between two computers to send data

• data is split up and is sent across a set path each pakcet takeing diffrent paths

• a several paths are found and data is sent across these while in use no other computers can use these paths

• data is sent over over physical disks

Answer explanation

a direct link is made while in use no other computers can use parts of the netwrk belonging to the link. A good example of this is public telphone system.

waht is packet switching

• a drect link is made betwwen two computers and data is sent acros the link

• data is put into a physical device and sent as a package to teh intenderd person

• data is split into packets and eachpakcet is given a path to follow and sent actross the network

• seveal links are made toa computer across a netwrok and these are tehn only used by these two computers to send data

Answer explanation

packets of data are sent across a netwrok where simalr trasactions of data are happaning at the same time

what is are packets

• a letter holding a physical memery with data on it

• data is split into smaller managebale chunks to be sent over a network

• anouther name for program

• a file in a pragram that is seperate teh the body

Reorder the following

• destiation and eror ching data and order put in packet

• data split into packets

• data is chekced for error packets not arived are sent for again then file made

• each packet is routed along the network

• data is recived and orded

Match the following

• contains error checking data like a check sum

• packet payload

• contains the ip of sender and receiver, the protocol being used and the number in sequence it is in

• what is time of life / hop limit

• packets aer put in order any ones not arived or any corupted are asked for again then put together

• what hapeens when packet arive at destination

• a peice of data found in the header that defines the tiem you should wait before data expiers

• packet tailer

• the body of data being sent

• packet heacder

what are routers jobs

• to connects two networks (e.g. wan to lan, wan to wan or lan to ISP)

• gives you internet

• to connect you to a wan normaly you ISP

• allows for data to be sent acros a network

what is a the job of a router

• to download data that is sent to it

• to send data acros a LAN

• the check ip of all incoming data to see if it for this network and diregard teh rest

• to read the ip of a packet and then send data to the next router unitll end found

not all nerworks use the same protocols when data is sent to a network useing anouther protocol what is used (a)  

waht is a MAC adress

• every computr device that can accses a network has a network interface card which is assighned a MAC adress wehn joining a network

• a computer has MAC adress to identify it by name this can be cahged if you want a diffrent name

• every computr device that can accses a network has a network interface card which has a uneque MAC adress to idetify it this is hard coded

what is a protocol

• a prtocol is an order by a computer to send a a certain peice of data

• a set of ruels governing how data should be communicated across computers

• a way of formating data for certain jobs