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.