Factors for choosing a network for a company
Size of the organisation
- –Needs can range from a small LAN to a global WAN.
- –Some communications media are limited by the distance they have to travel.
- –Amount of data processing required must also be considered.
How the system will be used?
- –What type of applications do users require? / Are the users going to require a wide range of applications?
- –Will they need large data storage? / Are they going to store a large number of data files?
- –From where will they operate the network e.g. at home in office or remote access from different locations. / Where does the processing get done?
Existing systems to integrate
- –More often networks are not developed from scratch but need to fit in with existing systems.
- –Sometimes an extension is required e.g. when a new branch office opens.
- –Therefore any new network must fit in with the existing operating systems and protocols.
- –It must support any peripherals already in use e.g. bar code readers, printers, etc.
- –Can the current stock of PC’s and peripherals be used on the new network?
Performance in terms of: reliability / user friendliness / capacity / speed of processing
- –Different parts of the organisation may have different performance requirements.
- –Real-time ecommerce system may require greater speeds / capacity / reliability.
Security Issues
- –Limit access to avoid as many security issues as possible.
- –Different organisations will have different needs.
Remote Access Features
—Check on hardware to see what needs upgrading
—Setting regular times for virus scanning/ check virus scanning has been done
—Check to see right number of licences
—Guide users through problems / Control stations to demonstrate /solve /show
—Check to see no unauthorised software loaded on machines
—Log off users who have forgotten to do so
—Check on components to see if any failing
—Shut down stations
—Rebuild stations / re setup stations / reinstall/update software
—Send instant messages
—Clear printer queues (at stations)
Advantages of Peer to Peer
—Cost saving - no server is needed, so all the computers can be the same
—Lower operating costs – less set up and maintenance costs
—No network manager is needed - all users take responsibility for the network (Knowledge).
—Easy to set up -they are the simplest of
computer networks, can be set up by anyone
—No reliance on a server no worry about the server breaking down
Disadvantage of Peer to Peer
—Knowledge - Users need more IT knowledge
—Peer responsibility users decide what resources others can use on their computer
—Security - Poorer security as resources are shared
—Back ups cannot be made centrally – this places the responsibility on all the users to back up their own data
—Harder to find files which are not stored centrally
—Network size -Only suitable for very small networks (15 or less)
Advantages of Client Server
—Network manager allocates access to resources on the network
—Users need little specialist knowledge as administration is performed centrally
—Security is better as it is centralised and one persons responsibility
—Backups and software installation can be done centrally
—Centrally stored files are easier to find
—More efficient / load tolerant for large networks
Disadvantages of Client Server
—More expensive - servers are expensive to buy.
—Cost of setup and maintenance is higher
—Need specialist knowledge. Need a person with technical knowledge to manage network.
—Network operating systems require
technical knowledge to set up and maintain
—If server breaks down network is unusable
Different Topologies
- –Ring
- –Star
- –Bus
Advantages of Ring
—Computers and peripherals all linked together.
—Fastest network because data flows in single direction.
—No data collisions.
—Each computer has the same access to the network, meaning no one can hog the network.
—Cheapest network.
Disadvantages of Ring
—Limited to 10-15 machines.
—Faults are difficult to locate.
—If the network breaks, no computer works.
Advantages of Star
—Largest network (can hold many computers).
—Load tolerant (can connect many computers).
—Fault tolerant.
—-Easy to add more devices without distrusting the network (you don’t have to restart).
—Different speeds are available on different arms of network.
Disadvantages of Star
—Expensive due to cabling costs.
—Dependence on central hub/server.
Advantages of Bus
—Cheap - because of small amount of cable needed
—Easy to install- simple cable runs
—If a work station/terminal goes down the others will continue
Disadvantages of Bus
—Heavy traffic can cause network failure and delays
—Small networks – recommended up to 15 computers.
—If the backbone cable breaks, then you can’t use the network.
