A Networking Analogy
In the last blog we touched upon our PC getting connected to a server like Facebook, and showing the data in form of images and/or text. How are these data on the server getting downloaded to the PC and showing up in our local PC or laptop?
Let us try an analogy to understand this a little better. Let’s say you ordered a bed from a furniture shop and the furniture shop told you that they will deliver it to your home. Assume your home is in a complex and there are many houses in that complex.
The furniture shop dismantles the bed and makes into smaller packages. These smaller packages will be loaded onto trucks and the truck will deliver this to your home by checking your address. Let us assume for this bed it required multiple trucks to be loaded. Below will be how it will look like :-
The trucks(rather the truck drivers) are given the address of your house and at each signal in the junctions there is a direction board which tells the truck which direction to take for them to reach your house. Trucks follow the correct direction as told in the direction board and they reach your house correctly. Once trucks reach your home
So at high level these are the steps done for the bed deliver from the furniture shop:-
- User or buyer in this case make a request to get the bed for his house
- The furniture store receives the request.
- Bed is dismantle and made into smaller pieces that can be loaded on to trucks to carry
- Sent the trucks to house by providing house address
- On the way the trucks will check for the directions by seeing the direction board and cross check with your home address to find the right route.
- Follow the sign in each intersection and finally reach house
- Once the trucks reaches your home it unloads and assembles your bed
- You get a complete bed in your home after proper assembly
What this has to do with networking. Let us keep it simple as of now. There is information or data(image/text) on the server. When your laptop browser(like Chrome/Firefox) connects to the server to get these information, the information are carried to your browser through the internet. How these information/datas are carried to your browser from the server is in a similar method how the trucks are loaded and sent to your house.
Instead of house in the world of network it will be your laptop/computer
Instead of furniture shop it will be the server from where you requested information
Instead of bed you will be requesting for data in form of image, text, video etc..
Instead of trucks it is going to be packets and these multiple packets contain the information that you have requested for
Instead of roads in the networking world it will be connections using wired/cable or wireless connectivity
Instead of sign boards and signal junction it will be routers in the networking world.
Well there are many other components that plays a role, but for now lets consider the most important element for the things to get working.
At very high level these are the steps:-
- User make a request to get the data to his computer
- The server receives the request. Server can be Facbook, Google etc
- The data into small chunks called packet to be carried over the internet
- Send these small chunks of data from the server to your laptop browser.
- On the way through the internet check at each router for your laptop’s location.
- Follow the information at each of the router one by one
- Once packets reaches your laptop, it assembles back those chunks in correct order
- You get the complete data from your server on your laptop after the assembly
In this scenario the furniture shop is your server and your house is the PC or laptop. The road that connects your house and furniture shop is the network. The bed along with the mattress will be delivered to your house possibly in a truck or multiple trucks based on the size of the truck and number of items the furniture shop wants to deliver to home. Remember there will be a lot of signals and junctions where these trucks need to take the correct turns (please forget about Google maps for now) to reach your house and if the correct turns are not taken the furniture does not come to your house.
When the truck starts from the furniture shop what it first checks is the town that your house belongs to and as the truck navigates through the road these trucks look for the town name board and take diversions accordingly. Once it reaches the town the truck driver looks for the apartment complex name, then your house number/name and finally it gets delivered to the house. Remember the bed is dismantled and all the pieces need to be fixed in the right order for you to get the bed in the way you saw it in the furniture shop.
By and large this is how the PC communicates with the server and gets the data in terms of image/text to your laptop. Here the furniture shop is the server, your house is the laptop, the road is the network, directions are the route, town is the major subnet, your house number is the IP address, the room in which the bed is kept is the port number, the trucks are the IP packets. Don’t get overwhelmed with all these. We will take one by one these items and explain in detail in the coming sessions. For now let us just understand that there is a similar mechanism happening in the network to deliver the content(bed in this analogy) to your laptop.