50 lines
1.9 KiB
Markdown
50 lines
1.9 KiB
Markdown
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---
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tags: [networks]
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created: Saturday, August 03, 2024
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---
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# Internet fundamentals
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The internet is a _[network](Network_fundamentals.md) of networks_. A globally
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connected set of computer networks that all use a suite of common
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[protocols](Network_protocols.md).
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The protocols governing the communication between networks on the internet are
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specified in the **Internet Protocol Suite**.
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This combines two protocols:
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- **TCP**
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- The Transmission Control Protocol
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- **IP**
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- The Internet Protocol
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Hence the Internet Protocol Suite is also known as "TCP/IP".
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The TCP/IP is a network stack comprising four layers, each with its own
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protocols. From the top:
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- The [Link Layer](Link_Layer_of_Internet_Protocol.md) concerns communication
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between devices on the same local network. The transfer of information once it
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has been received from the internet or its transfer between devices before it
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sent out into the internet. Ethernet and WiFi are two core protocols utilised
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at this layer.
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- The [Internet Layer](Internet_Layer_of_Internet_Protocol.md) is concerned with
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communication accross networks. It is responsible for identifying hosts on the
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inter-network by their addresses and routing data from network to network.
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- The [Transport Layer](Transport_Layer_of_Internet_Protocol.md) creates a
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commmunication channel between two hosts using ports and sockets.
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- The [Application Layer](Application_Layer_of_Internet_Protocol.md) concerned
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with software that utilises information received and sent over the internet,
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for instance web pages and emails. This is the highest level of abstraction
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for which all the lower levels serve as "plumbing". Examples of protocols
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operative at the Application Layer include HTTP and SSH.
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See:
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[Example_scenario_internet_data_transfer](Example_scenario_internet_data_transfer.md)
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