Network Resources

Local Area Network (LAN)

- A network in which the cimputer systems are all situated relatively close to each other.

- Since the distances are small, direct physical connection is possible.

- Network connections are normally wire cables, wireless links or fibre optic cable.

- A LAN usually serves a single organisation. 

Metropolitan Area Network (MAN)

- A network covering a highly populated area.

- The network servers the inhabitants of a built-up area (town / city), rather than an individual organisation.

- Uses fibre optic cable and wireless to provide a powerful service.

- Close proximity of users make it cost-effective.

Wide Area Network (WAN)

- A network in which the computers are geogrpahically remote.

- WANs make use of a range of connection methods typically public telephone links, undersea cables and cmmunication satellites.

- Often a WAN links the LANs in a geographically spread organisation.

- A LAN is spread over a small geographical area/a single building/office 

-  using cables/Wi-Fi/wireless/fibre optic technology 

- It provides services for a single organisation

- A MAN covers a highly populated area/a large town/city 

- using fibre optic/ wireless technology 

- It provides services for a community of users

Manages network resources

... such as storage

... files

... hardware devices/peripherals/printers

... communications/email

- Acts as a connection point for a number of network computers/nodes

- Checks the destination/IP address of data packets

... and forwards them to the intended recipient

Regenerates data transmission signals... that have been attenuated

- Network card connects a computer to a LAN 

- so that it can communicate with the file server 

- It provides a port for connecting a network cable/Ethernet cable

Wireless Access Point (WAP)

- These are hubs on the LAN that allow wireless connection.

To connect a computer to a network/router 

- using Wi-Fi/Bluetooth 

- in a hotspot 

- using radio transmitters/antennae 

- A media converter changes the physical signals where different types of network link meet.

-  For example, between fibre optic cable and twisted pair cable.

- The IP address is set by the ISP

- It is linked to the physical location of the device

- This will change/update with the location of the device

- IP addresses use 32 bits/4 bytes

- Each device has a permanent/fixed MAC address

... set by the manufacturer

... and embedded on the network card

- MAC address use 48 bits/6 bytes

- There is no dedicated/central server

- All computers have equal status

- Each computer is a supplier of resources and a consumer of resources

- A network organised around one or more servers

- The server maintains a database of authorised users, passwords and access rights

- Usually, but not always, a server acts as a file server but its prime function I to provide the security for the network

-  can make use of resources available at one or more servers – e.g. hardware such as a printer, software such as an application

- One advantage of the client-server relationship is that the server does the required processing, only the results being sent to the client thus reducing network traffic

- Another advantage is that resources are in one place and there are no problems caused by its physical distribution