Networks and topology  Lesson Objective: Understand the main terminology about networks.  Learning Outcome: Understand the different types of network and the advantage of each.

Reasons for using networks  Shared resources (like printers)  Shared software and data  Fast communication  Cabling expensive  Faults can affect the whole network  Security issues

What were those reasons?  What are the advantages of using networks  What are the disadvantages of using networks?

The two types of network  LAN Local Area Network Close geographical proximity Uses wire cabling, fibre optics or radio signals  WAN Wide Area Network Dispersed geographical proximity Uses modems and telecommunication technology

What are the two main types of computer network?  LAN Local Area Network Close geographical proximity Uses wire cabling, fibre optics or radio signals  WAN Wide Area Network Dispersed geographical proximity Uses modems and telecommunication technology

Topology  The topology describes the way in which a network is connected together. This usually applies to LAN.  Three main types: StarLineRing

Star Topology  Fast traffic speeds  Robust- problems are isolated  Expensive to set up  A problem with the central hub will disable the network

Line (or Bus) Topology  Cheap (less cabling)  Easy to add new computers  Slow if there is a lot of traffic  A problem with the central cable will disable the network

Ring Topology  Cheap to expand  Fast – data flow is one way  Slow if lots of users  A problem with one computer will disable the network

Connecting to the network… A computer needs a Network Interface Card (NIC) to connect to a network. A cabled network tends to be more reliable. Wireless connections are more flexible.

Client-Server Vs Peer to Peer  Specialised roles  Easier security and management  Easier to control and backup  Needs network manager  Dependent on server  Computers have equal status  Easier to set up and maintain  No dependency on server  Difficult to backup  Security and management issues

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