How torrents work

Torrents: Everything you need to know

Torrents — Every time I hear this word, the only things that come to my mind are free movies, games, and cracked software. But we don't know how they work, and there are various concepts involved in "seeds". Therefore, through this article we will understand what torrent download is from a technical perspective.

What is a "seed"?

A "seed" is a link to a file location on the Internet. They are not a file, they just dynamically point to the original file you want to download.

For example: If you click Google Chrome[1], you can download the Google Chrome browser from Google's servers.

If you click that link again tomorrow, or next week, or next month, the file can still be downloaded from the Google server.

But when we use "torrent" downloading, it does not have a fixed server. The files were downloaded from other people's PCs that had been previously downloaded using "torrents."

How do Torrents work?

Suppose there are some videos on ‘A’ and it wants to download them as “seeds”. So, he creates a “seed” and sends the link to ‘B’, which contains information about the exact IP address of that video on the Internet. So, when ‘B’ starts downloading that file, ‘B’ connects to ‘A’s computer. After ‘B’ has finished downloading the video, ‘B’ will start to act as a seed, that is, ‘B’ will allow other ‘C’ or ‘D’ to download it from ‘B’’s computer.

So everyone downloads the file first and then uploads it. The more people download, the faster the download speed. And in any case, if you want to stop uploading, no problem, you can do it at any time. This wouldn't be a problem unless many people downloaded and few uploaded.

The sower and the taker

The user who completes downloading a specific file will immediately become an uploader. Therefore, a downloaded person who can be downloaded by a new user is called a seeder.

And some users who have not completed downloading a specific file and are still downloading are called requesters.

piece

All "seed" files are independently split into fixed-size packets, so they can be downloaded in non-linear and random order. Each chunk is uniquely identified, so once all the chunks have been downloaded, they are stitched together to create the original file.

It is precisely because of this mechanism that if you are downloading a file from someone, if he stops uploading for some reason at this time, you can continue to download from other seeders without starting from the beginning. download again.

Peer

The peer refers to the requester currently connected to you. A requester that is uploading, regardless of how many blocks it has downloaded, is a peer.

For example:

A user who has downloaded the first 50 chunks of a file is a requester, however, he uploads these files at the same time, and you only have the first 10 chunks, so you can download up to 50 chunks from him. At this time he becomes your counterpart.

Best Practices

When you download a "torrent", always choose the largest seeder. This is the best experience.

There is no minimum standard here, but just make sure you choose the largest seeder.

Laws related to “seeds”

The laws related to "seeds" are no different from other laws. Like anything else protected by copyright, infringement will be punished by law. Most governments block torrent sites and protocols, but torrenting itself is not harmful.

"Torrents" are very useful for quickly sharing files, and they are used to share software in the open source community because they can save a lot of server resources. However, many people use them because of piracy.

Conclusion

Torrenting is a perfect technology to reduce the load on the server. "Torrent" downloading allows us to increase the download speed to the limit of the network card, which is very good. However, on such a decentralized server, piracy becomes an inevitable occurrence. It is our moral responsibility to limit the content we share and never download pirated content.

Please share your experience of using "torrents" in the comments below, and share your favorite "torrent" websites that are legally allowed to download.

---

The above is the detailed content of How torrents work. For more information, please follow other related articles on the PHP Chinese website!