Introduction to Networking: How the Internet Works
Internetworking Layer (IP)
This is part of the book "Introduction to Networking" at www.net-intro.com
Now that we can move data across a single link, it's time to figure out how to move it across the country or around the world. To send data from your computer to any of a billion destinations, the data needs to move across multiple hops and across multiple networks. When you travel from your home to a distant destination, you might walk from your home to a bus stop, take a train to the city, take another train to the airport, take a plane to a different airport, take a taxi into the city, then take a train to a smaller town, a bus to an even smaller town, and finally walk from the bus stop to your hotel. A packet also needs to take multiple forms of transportation to reach its destination. For a packet taking its "trip" to another country, the "walk", "bus", "train", and "plane" can be thought of as different link layers like WiFi, Ethernet, fiber optic, and satellite.
This is part of the book "Introduction to Networking" at www.net-intro.com
Now that we can move data across a single link, it's time to figure out how to move it across the country or around the world. To send data from your computer to any of a billion destinations, the data needs to move across multiple hops and across multiple networks. When you travel from your home to a distant destination, you might walk from your home to a bus stop, take a train to the city, take another train to the airport, take a plane to a different airport, take a taxi into the city, then take a train to a smaller town, a bus to an even smaller town, and finally walk from the bus stop to your hotel. A packet also needs to take multiple forms of transportation to reach its destination. For a packet taking its "trip" to another country, the "walk", "bus", "train", and "plane" can be thought of as different link layers like WiFi, Ethernet, fiber optic, and satellite.