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