Once upon a time there was a small mountain town that was trying to get all of its citizens connected. The mayor had heard about TCP/IP, the model for communication between computers, and thought it would be the perfect solution to help them all stay in touch.
But first, they needed to build the infrastructure, which would be the physical layer. The mayor and his team set out to lay down cables and install networking hardware throughout the town, establishing an internet connection point for everyone.
Next, they needed to work on the network layer. This was where the mayor and his team worked out how to route messages between different addresses on the network. This layer also helped provide details on how packets could be reassembled and handled across the network.
Once the network layer was up and running, they had to set up the transport layer. This layer provided a means for the computers in the town to communicate with each other correctly, using things such as flow control, segmentation, acknowledgements and error checking.
Finally, the mayor’s team established the application layer. This layer allowed users to access services such as email, web browsing, file sharing and streaming media. All of these services could be used safely and securely over the internet connection that had been established.
The mayor was so pleased with the success of the project that he held a celebration for all the citizens in town. He proclaimed that thanks to the TCP/IP model, they were now able to stay connected with each other no matter how far apart they were.
