Networks

When considering local area networks (LANs) a number of variables need to be considered:

1. Type of network
   Peer-to-Peer or Client-Server.
   
2. Topology
   The physical layout of the network.
   
3. Media
   The method of connecting the computers together.
   This can be copper cable, fibre-optic or wireless.
   
4. Hardware
   This includes workstations, Network Interface Card (NIC), repeaters, hubs, bridges and gateways.
   
5. Software
   Software required for networks can include:
   DOS
   Windows
   Network Operating System (NOS)
   Drivers for the various hardware compenents
   (All hardware components need software to convert physical conditions into the digital signals that the computer understands.)
   
6. Standards
   Networks have been tested to work effectively within certain limitations.
   A number of standard specifications are available that should ensure this.
   An example is 10BaseT.
   The 10 refers to the speed that the network can operate at 10 x 10 = 100 megabits/second.
   Base refers to baseband (only one signal passes along the medium at a given time).
   The T could be a number that indicates the maximum signalling distance.
   In this instance the T indicates the media used (Unshielded Twisted Pair UTP copper cable)

TOPOLOGIES:

There are three main topologies employed in LAN networks:

• Bus
• Ring
• Star