From DaphneWiki

File Transfer Details

BitTorrent

DaphneLoader uses a built-in BitTorrent client [1] in order to handle file transfers. BitTorrent works by having everyone upload at the same time that they are downloading. This is known as peer-to-peer file transfers because every peer sends and receives from every other peer. The other people who are also downloading are your peers, so you will both upload to them and download from them.

Why BitTorrent?

The main advantage of using BitTorrent is that you can generally download files much faster than if you were trying to download from a central server.

Why don't you make it more obvious to the user that they are also uploading?

DaphneLoader is designed to be as simple as possible. I feel that if a newbie starts downloading a file and gets a message that they are also uploading, they will get confused and worried, which will prompt them to ask us to explain why they are uploading. My main goal is to minimize questions, so I am going to avoid anything that will cause people to ask questions, especially redundant questions. Users who are savvy will poke around the Daphne menu and notice that they are also uploading while downloading. Chances are, they already know about BitTorrent will understand immediately what's going on.

What is this about opening up a TCP port?

Since BitTorrent is a peer-to-peer system, it works best when all peers can connect to all other peers. If peers cannot connect to you, and you cannot connect to them, then you will only be able to connect to a subset of all peers. In practice, those peers who can receive connections from everyone download significantly faster than those who are 'firewalled'. Imagine that peers who can connect to everyone have about 3/4 of the bandwidth and peers who can't have maybe 1/4 of the bandwidth. This happens in practice all the time. Don't underestimate the benefits of being able to receive incoming connections.

File Transfers and the DVD Requirement

Some people wonder why they must download a bunch of data and insert a DVD.

What you are actually downloading

When you download certain games that warn you that you will need a DVD later, you are actually downloading the full games in encrypted form. The DVDs are only used for decryption and no actual data on the DVDs are converted and used.

Why does DaphneLoader seem to hide the fact that the DVDs are used for decryption?

DaphneLoader is designed to require the user to know as little information as possible in order to run the game. Therefore, all details that aren't required are hidden from the user in order to keep things simple. Those who want to learn more will search documentation like this in order to satisfy their curiosity.