Bargain Booze has also requested enhanced security to include CCTV running separately from the till systems, preferably handled externally. There should also be motion sensors and multiple panic buttons where all staff can access them. This should be available as a security bundled from an external company.
The actual network is quite simple for Bargain Booze. The most expensive needs of Bargain Booze are the routers at each site. Cat 5 cables are needed to connect between the router and the computers. An engineering kit to actually install the network would also be needed.
To provide the network, an outside line is needed that is provided by Bargain Booze’s ISP.
Physical Constraints of the Network
The system is going to connect several sites together and needs to work well. There are several options for a network such as this. The limited number of computers at each site reduces the need for an overly advanced system but the distance between the sites is going to be a major factor.
Bus
Bus topologies are one of the simplest ways of connecting together computers. Each computer is connected to a single cable that the signal can travel between them and at either end; a terminator is used to absorb the signal. This topology is passive and computers only ‘listen’ for the signal and do not move the signal further across the network. Because of this, only one device may transmit data at a time.
The simplicity of this networks means that it is very easy to install initially and then later extend. It also uses a lot less cabling than other topologies and requires no expensive equipment to set up, making it also much cheaper to implement than other topologies. Whilst this network isn’t the most efficient network it is suitable for small networks or temporary connections.
The main problem with this topology is that is relies on a single cable which is restricted to a certain cable length (depending on the type of cable used) and this will also restrict the number of computers that can be connected. Also, in the event of this cable becoming damaged, the entire network will go down and to fix this cable can be costly and time consuming.
This is a potential option. Having a Bus network at each site would be relatively simple and as each site is unlikely to expand within the shops in the future; this would not be a limitation. Each of the sites will then be connected together.
Star
The Star Topology is based around a single device (such as a hub, switch or router) and all the computers on the network connecting to it through UTP cables. This means that all devices have their own separate connection to the network. If a single cable has a problem, then only that computer will become disconnected from the network. As this topology commonly uses UTP cabling, it is restricted to a maximum cable length of 100 metres.
This topology is most suited for much larger networks and is frequently found in larger companies. It can also handle many more connections and this makes is very easy to expand.
Instead of the wires being the weak part of the network, in a star network it is the hub that causes problems if it goes down. It is also much more expensive than a simple bus network as it requires expensive hardware at the centre of all of the connections as well as more cabling.
A star topology is an option for Bargain Booze. Each site would have a star network and then all the sites will then be connected with an extended star. However, the lack of number of computers at each site means that this may be overkill for the number of connections needed but the reliability makes this an option, as does the relatively short distance between the computer and the connecting device.
Ring
Computers linked using the Ring Topology, will always be connected to two other computers, linking all devices together. Each computer forwards on the signal to one of the devices connected to it, allowing many computers to be connected to it. This topology relies on constantly working computers, if one goes down then the entire network will stop working. It is also slower and more expensive than a star topology.
Another major drawback is that when a computer is either added or taken away, there is major disruption to the network until ring is completed once again. This can make maintenance costly and time consuming and will lead to business delays.
A ring network would not be an option. It is more expensive than a star network but is much more limited in what it can do and how it is used. Rings should be replaced with stars in all but a few cases.
Bargain Booze will be using an Extended Star as shown in the network diagram below.
Analyse potential developments in networking technology which may affect the project.
The biggest potential developments are increasing bandwidth and reduced costs. Both of these could dramatically impact the network if what we need for the network was not either currently available or currently within our budget. For Bargain Booze, we do not need a high bandwidth network. As we are currently not even using all of the bandwidth available to us, any newer technologies that have more bandwidth would be too much for the network. It is also likely to be too expensive for a network such as Bargain Booze. Increased bandwidth tasks such as video conferencing would push Bargain Booze towards this, but as it is a simple business a standard wired network is possibly.
Fibre Optic cabling is the next step towards higher speed networks. Even though Bargain Booze is not using high bandwidth technologies, they must still be compatible if/when the entire country switches over to fibre. The system should also be designed so that Bargain booze may switch to cabling in the future if they need to.
The cost of equipment is constantly changing as newer equipment appears to replace it. Each time a new generation of kit comes out; it pushes the costs of older kit down. This means that being a generation behind is usually cheaper. Because the world of computing is constantly changing and improving; even second generation kit is almost always more than capable of carrying out required tasks. The only time newer kit is required is in extremely demanding situations.
A new standard for wireless is about to be released and this is called 802.11n. It is hoped that this is the technology that will push wired users towards wireless connectivity as both speed and range are vastly improved over the existing system. It is hoped that 802.11n will double the speed of wireless and so far, testing is saying that this is true. Making wireless faster and more secure could make it a substitute for situations such as Bargain Booze’s network where at the moment, wireless just isn’t justifiable.
Identify and calculate the cost of all the resources required.
