1. Network and hardware revision
By lawrence standen – d2lh

2. Network types Bus network: Ring Network: Star Network:
In a bus network all the workstations, servers and printers are joined to one cable - 'the bus'. At each end of the cable a terminator is fitted to stop signals reflecting back down the bus.
The advantages of using a bus network are that it is easy to install, it is cheap to install and it also doesn’t require much cabling
The Disadvantages of using a bus network are that if the main cable fails or gets damaged, the whole network will fail
as more workstations are connected, the performance of the network will become slower because of data collisions
every workstation on the network 'sees' all of the data on the network, which can be a security risk.
Places like high street stores or small businesses might use this type if Network
Ring Network:
In a ring network, each device (eg workstation, server, printer) is connected in a ring so each
one is connected to two other devices. Each data packet on the network travels in one direction.
Each device receives each packet in turn until the destination device receives it.
The Advantages of using a Ring Network is that this type of network can transfer data quickly (even if there are a large number of devices connected) as data only flows in one direction so there won't be any data collisions.
But, the Disadvantages of using a Ring Network is if the main cable fails or any device is faulty, then the whole network will fail - a serious problem in a company where communication is vital.
Places like medium sized shops might use this type of Network like pet shops or MOT places.
Star Network:
A star network, each device on the network has its own cable that connects to a switch or hub. This is the most popular way of setting up a LAN. You may find a star network in a small network of five or six computers where speed is a priority:
The Advantages of using a star Network is that it is very reliable – if one cable or device fails, then all the others will continue to work
high performing as no data collisions can occur.
The Disadvantages are that it can be expensive to install as this type of network uses the most cable, and network cable is expensive
extra hardware is required - hubs or switches - which add to the cost
if a hub or switch fails, all the devices connected to it will have no network connection.
For this type of Network, maybe a highly developed business/ businesses like banks or shopping stores like Next or River Island might use it.

3. Networks in general
HARDWARE: A router can form a LAN by connecting devices within a building. It also makes it possible to connect different networks together. Homes and businesses use a router to connect to the internet. A router can often incorporate a modem within the hardware. A modem enables a computer to connect to the internet over a telephone line. A modem converts digital signals from a computer to analogue signals that are then sent down the telephone line. A modem on the other end converts the analogue signal back to a digital signal which another computer can understand. Hubs, bridges and switches allow multiple devices to connect to the router and they transfer data to all devices on a network. A router is a more complex device that usually includes the capability of hubs, bridges and switches. A hub broadcasts data to all devices on a network. This can use a lot of bandwidth as it results in unnecessary data being sent - not all computers might need to receive the data. A hub would be useful to link up a few games consoles for a local multiplayer game using a wired LAN.A bridge is used to connect two separate LAN networks. A computer can act as a bridge through the operating system. A bridge looks for the receiving device before it sends the message. This means that it will not send a message if the receiving computer is not there. It will check to see if the receiver has already had the message. This can help save unnecessary data transfers, which improves the performance of a network. A switch performs a similar role to a hub and a bridge but is more powerful.. This makes a switch more efficient when demand is high. If, for example, a game involved lots of data being passed between machines, then a switch could reduce the amount of latency .Wireless access points (WAPs) are required to connect to a network wirelessly. WAPs are usually built into the broadband router. ADVANTAGES AND DISADVANTAGES FOR ALL OF THE NETWORKS Advantages: Communication – it is easy (and often free) to communicate using , text messages, voice calls and video calls. Roaming – if information is stored on a network, it means users are not fixed to one place. They can use computers anywhere in the world to access their information. Sharing information – it is easy to share files and information over a network. Music and video files, for instance, can be stored on one device and shared across many computers, so every computer does not need to fill the hard drive with files. Sharing resources – it is easy to share resources such as printers. Twenty computers in a room could share one printer over a network. Sharing software – it is possible to stream software using web applications. This avoids needing to download and store the whole software file. Disadvantages: Dependence – users relying on a network might be stuck without access to it. Hacking - criminal hackers attempt to break into networks in order to steal personal information and banking details. This wouldn't be possible on a stand-alone computer without physically getting into the room, but with a network it is easier to gain access. Hardware – routers, network cards and other network hardware is required to set up a network. At home, it is quite easy to set up a wireless network without much technical expertise. However, a complicated network in a school or an office would require professional expertise. Viruses - networks make it easier to share viruses and other malware. They can quickly spread and damage files on many computers via a network.