Network topologies, protocols and layers (1.3) GapFill

Networks can be connected in a number of topologies with their own benefits and limitations. Examples of topologies include star networks, which connect devices  with a central switchwirelesslyusing multiple WAPsdirectly to one another, and mesh networks, in which devices are connected  directly to one anotherwith a central switchusing wiresusing multiple WAPs.

Because of the way in which star networks are arranged, if one of the device's connections fails then only that device will be affected. However, star networks  cannot make wired connectionscan be expensive because of hardware costsdo not allow multiple devices to send data simultaneouslyare complicated to set up, and if the switch fails, then  devices will be damagedsome of the devices may failthe network is unaffectedthe entire network fails. Setting up a mesh network can be expensive because  it can require a lot of cablingonly fibre-optic cabling can be usedmany servers are requiredmesh networks use more energy than other types of network, but when a device's connection fails in a mesh network,  data transfer speeds increaseit might not even isolate that deviceit only isolates some of the nearby devicesthe entire network fails. Both of these networks  allow multiple devices to send data simultaneouslyare examples of client-server networksare unable to encrypt dataare examples of peer-to-peer networks.

Networks use a number of different protocols so that  data transfer speeds can be increasedevery device can understand the signals being sent by other deviceslatency can be reducedthe size of data signals can be reduced.Ethernet and Wi-Fi are two  wired networkswireless networkstopologiessets of protocols that determine how data is transmitted across a network. In  wired Ethernetwireless EthernetWi-Fiprotocol networks, if two signals are sent along the same wire at the same time, the signals collide and so both signals are corrupted and must be resent.

 Wi-FiprotocolWireless EthernetWired Ethernet networks limit interference between signals by splitting the available network frequencies into overlapping channels, although signals on a channel can cause interference with any channels that it overlaps. These networks can use a 5GHz or a 2.5GHz  Ethernetfrequencymicroprocessorprotocol channel. A 5GHz network has  more non-overlapping channelsfewer non-overlapping channelsfewer connected devicesmore connected devices that can be used simultaneously without causing interference,  has a longer rangebut supports fewer serverssupports more serversbut has a shorter range and is less able to go through walls. 

Bluetooth, meanwhile, is another wireless protocol which you may be familiar with using – to connect headphones, for example. It is good for  long-termlong-distanceshort-distanceshort-term networking.