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Networking - Coggle Diagram
Networking
Hardware
Router
A router is the device that is the connection between LAN and WAN, however it often has other components built into it.
It is responsible for forwarding data packets between different computer networks. The packets are forwarded between routers using various protocols including the IP (follow the yellow branch).
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Hub
A hub receives data from computers connected to it. Data on a Local Area Network is carried by a data type known as a frame (once ready for transmission on the internet this is transferred to packets).
When a hub receives a frame it amplifies it and then transfers it to a destination PC by broadcasting it to all other devices on the network.
Switch
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Once it has learnt the addresses it only sends data to the device that it needs to; this means that there is less data on a network meaning that transfer of data is significantly faster.
Network Interface Card
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The NIC stores the information that identifies an individual device on a network, the MAC address. Each NIC has it's own unique, and unchangeable MAC address
Wireless Access Points
Provides a means to allow Wireless devices to access a network. The wireless access points themselves are physically attached by cables to the network.
Layers
Application Layer
This encodes data being sent so that it will be understandable by the recipient. It uses HTTP(S) and FTP
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Network/Internet Layer
This attaches the IP address of the sender so that the computer that receives it knows where it has come from. It also attaches the address of the host and destination IP address
Link Layer
This attaches the MAC address of the sender and the recipient allowing for the packet to be sent to a specific device on a LAN
Protocols
For Websites
HTTP
Hypertext transfer protocol. Requests that the web server transmits the requested web page to the viewer's web browser.
HTTPS
Hypertext transfer protocol secure. Works in a similar way to HTTP but as this data is transmitted it is encrypted. This means it requires a key to be read.
For Emails
POP
Post Office Protocol. POP receives and holds emails until they are picked up by a user. When the user checks their email it is downloaded from the server and then deleted it from the server.
SMTP
Simple Mail Transfer Protocol. This protocol allows for emails to be sent between email servers. This is particularly relevant when the server and recipient have different email providers .
IMAP
Internet Messaging Access Protocol. This method of receiving emails is more suited to users who have multiple devices. This is because it maintains a copy of the email on the server until it is deleted by the user.
Other
TCP
Transmission control protocol. This is responsible for how messages are broken into packets and reassembled at the destination. It is also responsible for error checking and re-sending lost packets.
FTP
File transfer protocol. Used to transfer files across a client server based system (look at red branch). It uses separate control and data connections.
IP
Internet protocol. This allows for devices to be identified on the internet and allows for appropriate packet routing
DNS and URLs
URL
Websites are stored on webpages that are connected to the internet. Each website has it's own IP address. IP address are difficult to remember so web sites are given a domain name or a Uniform Resource Locator (URL) .
DNS
When you type in a URL to the address bar this is sent as a request to the a domain name server. This is part of the Domain Name System and it controls how webpages are retrieved.
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Connection Media
Ethernet
Ethernet cables are the most common method of connecting devices on a network. They are sometimes referred to as unshielded twisted pair cables (UTP). It is made of copper wires within a plastic sheath twisted around each other and covered in another plastic cover.
Cat5e and Cat6
The difference between the two is that Cat 6 has a higher bandwidth and therefore can send a higher amount of data over a specific period of time; it is therefore more suited to industrial uses.
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Cat 6 cabling is capable of allowing data to be transmitted over longer distances with a signal being boosted.
Co-axial
This connection method is again based on the use of a copper wire. Co-axial cabling is often used for cable TV and broadband.
It has a higher bandwidth than Ethernet cable and can allow for greater distances to be travelled before being boosted.
It also has significantly more robust construction. This stronger construction leads to less interference or distortion of the data.
Fibre Optic
This is becoming the preferred method of data transfer using broadband. It is still fairly uncommon in the home as Optical Network Interface Cards are very expensive.
Fibre optics makes use of pulses of light to transfer the data. They have much greater bandwidth and are not affected by electromagnetic interference which can lead to loss of data.
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Network Topologies
Star Network
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This provides a number of advantages including that if one cable fails only that workstation is affected and the performance is consistent even when being heavily used.
Conversely it can be costly to install because of the extra hardware and cabling and also if the central switch or the server fails then the whole network is affected.
Mesh Network
In this type of network each node is connected to every other- a node is simply a device on the network.
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To connect to the internet only one of the nodes needs to be connected to a modem, this connection is then shared across the rest of the network. The nodes share information with the next nearest node and so on.
As a device is added this simply adds in the extra node. Using a full mesh network allows for data frames (similar to packets) to be sent via the quickest route.
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