Many of the readers who use the internet regularly may have downloaded torrent files. Even if you don’t download, you should be familiar with the word ‘torrent’! In this article we will try to give details about all the details of torrent.
Torrent is actually a type of file. The method by which this file is downloaded is called bit-torrent. Although many people like to call this system ‘torrent’. Bit-torrent is a system that can give you a very fast download service using very little internet bandwidth. This is because the download method used in the bit torrent system is completely different from all other download methods.
Traditional client-server download system
We are all used to downloading songs, movies etc. from the internet. Usually the way we download files from the internet is the client-server downloading method. It is important to know this method well. Otherwise the difference between bit-torrent with this download system will not be clear.
• First you go to a webpage from the computer and click on the link to download the file.
• Your computer’s web browser (client) requests the server (a computer in the center, which contains the webpage and the file you want to download) to transfer a copy of the file you want to download.
Then that file starts to be copied to your computer. And the transfer is controlled through a protocol, such as: FTP (File Transfer Protocol), HTTP (Hypertext Transfer Protocol), etc.
Now the main thing is, you are not alone in downloading the file from the server! Suppose that file is quite large in size and popular, then the demand to download that file from the server will be much higher. So it is not surprising that the download speed decreased naturally at that time. Again, this download is quite dependent on the type of protocol, the amount of traffic on the server, etc. As a result, your download speed will fluctuate considerably from time to time.
We learned how the client-server downloading method works. Now let’s see how a peer-to-peer (or P2P) file sharing system works.
Peer-to-peer file sharing
Bit-torrent uses peer-to-peer (or P2P for short) file sharing systems. In this method you have to use a software. The job of this software is to find out which computer has the file you need. ঐ Computers are actually ordinary computers, just like your computer, not server-server client-server computers. These are called peers. P2P file sharing is done in a few steps like this-
• First a request for the required file is sent by launching the P2P file sharing software.
• The software queries the other computer to find the file. The software will look for the file on computers that are connected to the same software at the same time.
• The download starts on your computer just when the file sharing software finds a computer with those files.
If you keep the software open after downloading, other connected people will be able to download .torrent files from your computer. Some people disconnect their desired file immediately after downloading so that no one else can take the file from their computer. This is called leeching.
The difference of bit-torrent with normal P2P
Bit-torrent has several differences with other P2P file sharing. For example, the bit-torrent protocol does some of the file tracking work with a central server. This is called a tracker. Another difference is the Tit-for-tat method. This method means you have to file if you want to get the file! The more files you share with everyone, the higher your download speed will be. If you just download but do not share your file, that is Leeching, then you can not expect good download speed! And this is what eliminates the problem of Leeching in bit-torrent. As a result, you have to share some files for yourself! Finally, BitTorrent starts downloading different parts of the file at the same time for maximum use of internet bandwidth. So naturally the download speed from the client-server method is also higher.
The way bit-torrent works
What we’ve been talking about for so long can be called the context for understanding bit-torrents. If the reader understands these well, it should not be difficult to understand the working method of bit-torrent.
Now we will learn how to download a torrent file to your computer.
• You open a webpage and click the link to the file you need.
• As soon as you click, the bit-torrent client software communicates with a tracker so that it can find the Seed computers (computers that have the complete file). At the same time he finds computers that have parts of that file (they are called peers; that means they are downloading or uploading the file at that time).
• Tracker keeps track of all the Seeds and Peers in the Swarm (computer in the download or upload process).
• The tracker allows bit-torrent client software to download fragments of that file from other computers in Swarm. And at the same time different pieces of that file start downloading to your computer at the same time.
• If you keep the bit-torrent client software open even after your desired file has been downloaded, other people in Swarm will have the opportunity to download the .torrent file from your computer. And if you don’t want to take that chance, your next download speed will be lower according to the tit-for-tat system!
The higher the number of computers in Swarm, the higher the download speed. Because having more computers in Swarm means having more resources for the file. And this is why BitTorrent is so effective for downloading large-scale files. And that’s how exactly torrents work.