Open a web page, here we will see how is this happening in the system. TCP/IP protocol is what makes sending and receiving of data across the internet from some remote server or remote end user. But how data knows how to find us and how we know how to find the IP addresses of the web servers where are the pages saved? Data is not even going on the same way when we send something (a request) to the server, and the server response in shape of data flowing to our computer. Internet is big system that knows in every moment how to find the best route to some device connected somewhere in between all this nodes. But how is this data traveling across the wires, fibers and air? Data is divided in small packets. Every time we send a request to a server, our request first must be divided in smaller packets of the same size and then they are going to DNS – domain name server that will have the information of direction in which direction request must be forwarded. DNS have the knowledge of IP addresses for all URLs that are registered on the internet, and with this database he can translate our request for webpage in the same request but pointed to IP address of the server on which the webpage is stored.
So, when you open your web browser application on the computer and type in the URL of this page www.howdoesinternetwork.com, the computer must connect to the server where this page is stored and download this page to the computer in order for you to see it. Your request goes through ISP and in some point hits the DNS – domain name server who will look in his huge database and match the domain name you’ve entered with the IP address of the proper server. If the DNS server does not find a match, it will forward the request to next DNS server who maybe has more information. Not all DNS servers have all the data about all the domain names and they addresses.
When the server is found he will respond by sending the requested files in a series of packets. Packets are files divided into small pieces that range between 1,000 and 1,500 bytes. Packets have some extra data called headers in the beginning and footers at the end and that data tell computers what’s in the packet and how the information can be put together with other packets to recreate an entire file that has been sent. Each packet travels through the internet network into your computer. Packets don’t necessarily all take the same path they will usually travel with the path of least resistance, which is the best path in that moment. I fact, that is the most powerful feature of internet. Packets can travel with different routes and in this way avoid congested paths and come to their destination even when an entire part of internet is down.
In case of different types of files the way that the network is making communication work is basically the same. VoIP calls, e-mails and other different files are also divided in packet and sent through the network to be recreated in the other end with the information in the header and trailer of every packet.