Week1-01_The TCP/IP Five-Layer Network Model

The TCP/IP Five-Layer Network Model

Table of Contents

• Physical Layer
• Data Link Layer
• Network Layer
• Transport Layer
• Application Layer

Physical Layer

Represents the physical devices that interconnect computers.

Data Link Layer

Responsible for defining a common way of interpreting these signals so network devices can communicate.

Ethernet(Protocol):The Ethernet standards also define a protocol responsible for getting data to nodes on the same network or link.

Network Layer

Allows different networks to communicate with each other through devices known as routers.

Internetwork: A collection of networks connected together through routers, the most famous of these being the Internet.
IP is the heart of the Internet and most smaller networks around the world.

Transport Layer

Sorts out which client and server programs are supposed to get that data.

TCP:Transmission Control Protocol
UDP:User Datagram Protocol

Application Layer

There are lots of different protocols at this layer, and as you might have guessed from the name, they are application-specific. Protocols used to allow you to browse the web or send receive email are some common ones. The protocols at play in the application layer will be most familiar to you.

Recap

You can think of layers like different aspects of a package being delivered. The physical layer is the delivery truck and the roads. The data link layer is how the delivery trucks get from one intersection to the next over and over. The network layer identifies which roads need to be taken to get from address A to address B. The transport layer ensures that delivery driver knows how to knock on your door to tell you your package has arrived. And the application layer is the contents of the package itself.

References

https://www.coursera.org/learn/computer-networking/lecture/BTLgy/the-tcp-ip-five-layer-network-model
https://en.wikipedia.org/wiki/OSI_model
https://www.sans.org/white-papers/543/