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How the Internet Works? (Part 1)

The dynamic, user-friendly interface of the Internet as we know it today, is breathed life into by a multi-layer global network system that connects hundreds of millions of computers.

If you are watching this video, it is because a sophisticated signal transmission system has been developed and implemented over the years.
Most likely the data in this video may have traveled thousands of miles before reaching your device.

In this video we will try to figure out how does the internet work by explaining where this data is coming from and which path they need to follow in order to reach every single user connected to the network.
The video you’re watching now is stored inside a Data Center. Data Centers are simply centralized location that provide important services such as data storage, backup and recovery, data management and networking.

JAES is constantly engaged in the supply of all the spare parts necessary for the proper functioning of these data centers, which they need to be constantly working, 24 hours a day.

Let’s see in detail the entire data transfer process…

A simple way to achieve this data transfer is to use a geosynchronous satellite. In this case a internet service provider sends a signal to this satellite via a special antenna, and then from the satellite the signal is sent to our mobile phone with the help of another antenna near to us.
However, this is not the best method to achieve a good connection: a satellite in fact orbits at a distance of over 22,000 miles above Earth’s equator, so the signal will have to travel a total distance of about 44,000 miles! This is because the signal is first sent to the satellite, and then from the satellite is sent back to the Earth to the right recipient. All this creates LATENCY which is a delay in receiving the signal due to the long distance.

The most efficient way to transfer the signal is through optical fiber cables, which thanks to a complicated network connect the data center to our device. Even our smartphone, despite being a mobile device is indirectly connected to these cables. The Cellular Radio Towers in fact are connected to this optical fiber cables network. Their antennas receive the signal from the underground network. Then the signal is converted into an electromagnetic wave, so as to be picked up by the antennas of our phone.

As we mentioned earlier, this video you are watching is stored inside a data center, more precisely inside a solid state device, this SSD represents the internal memory of a server, which is basically a more powerful computer. The primary function of this server is to store, process and deliver web contents to clients. These data are transmitted through the complex network of optical fiber cables and reach the right recipient thanks to IP addresses.

The IP address is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. Like our home address, the IP address allows us to receive the right information to our device. It is the job of our internet service provider to assign us a unque IP address which we can also see it in its entirely on our laptop or smartphone.

Even the server in the data center has their own specific IP address. In fact, the IP addresses of any website are stored in a server, but since it is not very convenient for us to remember all these numeric strings, many IP addresses are associated with DOMAINS. For example: YouTube.com or facebook.com.
Furthermore, many domains cannot be associated with a single server, especially giant web sites like Youtube or Instagram that contain a lot of information. Usually these companies have their own personal data center.

We all access information online through domain names instead of the complex IP address numbers.
Each web site has its own domain. But how does the internet track all these names? Simply with the help of a huge naming system called DNS, namely "Domain Name System". This system is basically the phonebook of the Internet. We use a phone book every time we don’t remember a certain person’s phone number, but we remember exactly his full name. So, it will be much easier for us to find his number through his name, then the other way around. The DNS system applies the same concept to the internet. Every internet service provider has access to a DNS server.
So to recap: when we enter the domain name, our browser sends a request to the DNS server to get the corresponding IP address. After getting the IP address, our browser simply forwards the request to the data center, to the respective server. Once the server gets a request to access a specific website the data flow starts. The data is transferred in digital format via optical fiber cables, more specifically in the form of light pulses. Very often these light pulses have to travel thousands of miles before reaching their destination and during their journey they often have to go through tough terrains such as hills, mountains or even under the sea.

For this reason there are a few global companies dedicated to delivering subsea network connectivity on a global scale. These companies are specialized in submarine cable installation.
In the second part of this video we will see how fiber optic cables are laid on the seabed and how the data finally reaches our laptop and smartphone.

In the first part of this video we had the chance to understand how Internet communication works.
Now we are going to see how fiber optic cables are laid on the seabed and how the data finally reaches our laptop and smartphone.
Submarine cables are laid down by using specially modified ships, sometimes even purpose built ships, that carry the submarine cable on board and slowly lay it out on the seabed. The cable is not simply left to sit on the ocean bed, but is actually being fed into a plow, that lays the cable into a trench.

Currently 99% of the data traffic that is crossing oceans is carried by undersea cables. Over 550,000 miles of undersea cables guarantee web and telephone connections to all continents except Antarctica, which is still connected via satellite.

During this period Google says that an innovative submarine fiber-optic cable it’s building across the Atlantic Ocean. It will connect the American and French shores and it will be the fastest of its kind, transmitting more than 160 terabits per second, enough to broadcast over 12 million HD videos per second!

To withstand wear and salt water damage, this cable will have a double protection of galvanized steel.
Google ensures its cable is sheathed in a Kevlar-like protective coating to keep the sharks from chomping through the line. This is a super-strong bulletproof material because of its high tensile strength-to-weight ratio.

Like we already said in our previous video, the optical fiber cables carrying the light pulses are stretched across the seabed to our doorstep where they are connected to a router. The router converts these light signals to electrical signals. Then, an Ethernet cable is used to transmit the electrical signals to our laptop.

No one person, organization or government controls the Internet. But since the Internet is a global network it has become important to have an organization to manage things like IP address allocation and domain name system management. This is all managed by a nonprofit organization institution called ICANN located in the USA. ICANN stands for Internet Corporation for Assigned Names and Numbers.

ICANN helps to keep the web safe by developing and enforcing policy on the Internet’s unique identifiers. This has helped to improve data transfer rate over the year. Today, one amazing thing about the internet is its efficiency in transmitting data. This video you are watching is sent to you in the form of a huge collection of zeros and ones. In order to make the data transfer more efficient these zeros and ones are chopped up into small chunks known as packets and transmitted. Usually each packet consists of 6 bits and contains all the necessary information inside, such as IP addresses of the server and our device. With this information the packets are routed towards our device. It’s not necessary that all packets are routed through the same path and each packet independently takes the best route available at that time. Upon reaching our device the packets are reassembled according to their sequence number. If it’s the case that any packets fail to reach us and acknowledgement is sent from our device to resend the lost packets and complete the process.