What is torrenting and how can companies block it Found on Spiceworks

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Torrenting definition
torrenting: [tore-rent-iing] noun.
Torrenting is the act of using computers to download or propagate files through a peer-to-peer network that uses the BitTorrent protocol. This protocol allows for file sharing between many computers spread across the internet. Torrenting involves a potentially huge number of participating devices simultaneously sending and receiving small fragments of the same file or files, which are reassembled when fully downloaded to form a complete file.

Because the distributed nature of torrenting means participating computers do not need an entire file to share (AKA seed) it, torrent participants can download pieces of the same file from many sources scattered across the internet at the same time. Therefore, torrenting provides a mechanism to get around limitations on typically slow internet upload speeds on individual connections, making torrenting a quick and efficient way to distribute large quantities of data by enlisting the help of many computers and internet connections at once.

To participate in torrenting, a computer can run a BitTorrent client application, such as μTorrent, that manages communications with and data transfers between the other computers sharing the same file(s). Torrent clients also parse torrent files, which contain metadata on the file or group of files being shared within a torrent as well as information that can be used to locate other computers in the same peer-to-peer torrent network. A computer can participate in multiple torrents at once: For example, one torrent for sharing a video file and another for sharing several PDF files.

Torrenting analogy
The classic analogy for torrenting is that of photocopying a book at a library. Imagine you have a 24-page book and you wanted to distribute copies of it quickly to many people.

Now imagine that you're in a library with one copy machine and you're the only person that can use it. Every time someone wants a copy of your book, you individually copy every page, then staple the copies of the pages together and hand it to the recipient. This method, which is similar to the traditional client-server file sharing model, works fine but isn't necessarily the fastest way to share a book. Additionally, because you're the only person that can copy the book, it will be difficult for others to obtain a copy once you decide to stop sharing it.

Now imagine you're in a library with 24 copy machines that everyone can use. To speed the copying process up, you rip out all of the pages of your book and hand a single page to 24 different people who can then make copies of their respective page. Now, anyone that wants the book can get a copy of each page from these 24 people, then staple the complete contents of the book together to form the complete book. The original 24 people can also trade copies of pages with each other, until they have the complete book as well. 

Once someone has a more complete book, they can provide a copy of any of the pages they have to other recipients. So even if some of the original 24 people decide to stop sharing, recipients can still get the full book from others sharing the book. This example approximates how torrenting works on the internet.

Torrenting concerns
While the idea behind torrenting is pretty useful, torrents are often viewed by IT departments as a potentially dangerous nuisance for several reasons. And according to Spiceworks research, the vast majority of companies monitor IT usage of users to some degree, for example, to protect networks against online threats. Below is a list of concerns around torrents.

Torrents present a security risk

The sites that host torrent files often try to trick users into downloading spyware and malware, and often hackers create fake torrent files with links to phony installer files in an attempt to get users to install viruses on their computers.

Torrents are bandwidth hungry

BitTorrent clients often try to use all available download and upload bandwidth on a network. This means that torrenting in an office environment can bring internet connection speeds to a crawl, potentially affecting critical services and degrading quality of service for everyone. Additionally, if torrent usage goes unchecked, businesses might have to pay more unnecessarily for a faster internet connection.

Torrents are a legal liability

We've already established that torrents provide a great way for users to download and share large amounts of data quickly. This has led to BitTorrent clients becoming a popular way to distribute copyrighted music and movies, or even material that's inappropriate for the workplace, which can create legal problems for companies, such as lawsuits from content owners.

Blocking torrents
There are many ways to prevent users from torrenting on company networks. Here are a few of the methods you can use to stop the practice so you can protect your network from security threats, conserve bandwidth, and  avoid legal issues:

How to block torrents

Install application-level firewall filtering to block torrents
Enable user access controls that prevent users from installing torrenting apps
Run a packet sniffer like WireShark to detect torrent activity
Use network management tools like Spiceworks to detect instances of torrent clients
Prevent users from visiting sites that host torrent files
Block downloading of files with the .torrent extension
Use a network bandwidth monitor to find heavy bandwidth users
 

Edited August 8, 2018 by Archiee
Title edited