ICT WJEC A2 - TOPIC 1: NETWORKS

ADVANTAGES OF RING TOPOLOGIES:

1) not dependant on a central server       2) faster speeds possible because of uni-direction         

DISADVANTAGES OF RING TOPOLOGIES:

1) if there is a break in the 'ring', then the whole network fails   
2) faults are difficult to locate
3) the network cannot stay running when a fault is being sorted out/ fixed     

ADVANTAGES OF STAR TOPOLOGIES:

1) fault tolerant (if one cable fails then other machines can still be used)
2) load tolerant (extra computers can be added- this will not reduce the performance as all computers have their own path to the hub)
3) easy to add computers to the star            

DISADVANTAGES OF STAR TOPOLOGIES:

1) higher costs (as more cabling)         2) dependance on the central hub 

 ADVANTAGES OF WIFI:

• allows inexpensive LANs to be set up without cables
• freedom of working anywhere a signal can be recieved
• use all over the world
• (health and safety)

DISADVANTAGES OF WIFI:

• high power consumption (this means that laptops may exhaust their rechargeable batteries)
• there could be security problems with encryption used
• limited range
• transmission speeds are slower than cables

1) COST OF THE NETWORK - the initial purchasing of equipment/ installing the network and maintaining the network/ training staff to use the network...

2) SIZE OF THE ORGANISATION - LAN or WAN?/ amount of data being processed...

3) HOW THE SYSTEM WILL BE USED - amount of storage needed/ what type of applications does the user require?...

4) EXISTING SYSYEMS TO INTEGRATE - generally systems are not developed from scratch... therefore it is important that it fits with the existing protocols and also that it suports the (existing) peripherals (eg. printer/ scanner etc.)

5) PERFORMANCE (in terms of reliability/ speed of processing...)

PEER-TO-PEER:

• COST saving (all computers are the same)
• STATUS: all computers have the same status
• EASY TO SET UP
• less SECURITY as the resources are shared
• BACK UPS cannot be made cetrally (this places the responsibility on the user to save and backup their own work)
• more ICT KNOWLEDGE required by users

CLIENT SERVER:

• COSTLY (servers are expensive to buy)
• STATUS: one machine is more important than the rest
• REQUIRES SPECIALIST KNOWLEDGE to SET UP and to MAINTAIN
• better SECURITY as it is centrallised and is one person's responsibility
• BACK UPS are made centrally
• the ICT KNOWLEDGE is needed for the person managing the network (specialist knowledge)

• see which users are using the network
• check on the sites that the employees visit
• check on emails that were sent when they should've been working
• guide users through problems
• send instant messages
• log off users who have forgotten to log off
• shut down stations