Recent Changes

employees up to date with the organisation's policies
WLANs (Wireless local area network) - no wires/cables other than the wiring that connects the WLAN access points together a WLAN uses either spread spectrum radio waves or infrared signals to enable devices to communicate with each other
Wi-Fi (Wireless fidelity) - wireless networking
using radio waves instead of cabling
Data translated into radio signal and decodes it

provide discussion forums
employees up to date with the organisation's policies
WLANs (Wireless local area network) - no wires/cables other than the wiring that connects the WLAN access points together a WLAN uses either spread spectrum radio waves or infrared signals to enable devices to communicate with each other

knows addresses of each device attatched to it (has them stored in the form of an internal table
when it is sent a packet from one device, it notes the address of the device that sent it and forwards the packet on to all the other computers
Routers -
Intranets
a website located on a private network within an organization
Firewalls prevent people outside the organization from accessing the intranet
Smaller than Internet<---global
traditional LAN
based - based on Internet protocols
a client-server relationship between computers, devices and the servers
each device is allocated an IP address and data are identifire using a URL data being transmitted uses HTTP
Useful?
local e-mail - sending messages within the organisation
getting members more in contact through e-mails and videoconferences
easier to share information acoss an intranet rather than sending memos
provide faster access to documents and statistics
sharing diaries, organizing meeting times
provide discussion forums
employees up to date with the organisation's policies

Firewalls prevent people outside the organization from accessing the intranet
Smaller than Internet<---global
advantage over traditional LAN
based on Internet protocols

when it is sent a packet from one device, it notes the address of the device that sent it and forwards the packet on to all the other computers
Routers -
Intranets
a website located on a private network within an organization
only for the use of members of that organization
Firewalls prevent people outside the organization from accessing the intranet
Smaller than Internet<---global

may amplify the signal before sending it on
passive hub - does not amplify the signal of the data packets but merely sends the data on its way
using MAC (Media Access Control) address of
more advance than a hub
data from any computer is transmitted to its destination without congesting the other ports
knows addresses of each device attatched to it (has them stored in the form of an internal table
when it is sent a packet from one device, it notes the address of the device that sent it and forwards the packet on to all the other computers
Routers -

Parity check - a means of verifying that data has been transmitted accurately
the bit at the start of the byte is called the parity bit, whilst the remaining seven bits are used to represent the data being transmitted
Network hardware
Network hub - connects computers together in a network and distributes data from one device to the others on the network
does not read any of the data in th packets which arrive from a computer, but just sends them on
may amplify the signal before sending it on
passive hub - does not amplify the signal of the data packets but merely sends the data on its way
Switches - can have a number of other devices connected to it. able to direct network traffic using MAC address of a data packet
more advance than a hub
data from any computer is transmitted to its destination without congesting the other ports
knows addresses of each device attatched to it (has them stored in the form of an internal table
when it is sent a packet from one device, it notes the address of the device that sent it and forwards the packet on to all the other computers

makes sure that data is delivered to the correct address
Handshaking - the initial communication between two devices that enables exchange of data to take place
parityParity check -
the bit at the start of the byte is called the parity bit, whilst the remaining seven bits are used to represent the data being transmitted