ZyXEL Communications NSA-220 User Manual

Page of 234
Chapter 8 Application Screens
NSA-220 User’s Guide
94
8.5.1  BitTorrent
The NSA includes a BitTorrent client for fast downloading and sharing of large files (such as 
educational public domain videos). With BitTorrent, you share while you’re downloading the 
file. BitTorrent breaks up the file and distributes it in hundreds of chunks. You start sharing the 
file as soon as you have downloaded a single chunk.
8.5.1.1  Torrent Files
Before using BitTorrent to download a file, you must first obtain a “torrent” file. The torrent 
file uses a .torrent extension. The torrent file has information about the file to be downloaded 
(and shared) and the computer(s) that coordinates the distribution of the file (called the 
tracker). Your BitTorrent client uses the torrent file to connect to the tracker to find out where 
to get the pieces of the file you want to download.
When you add a BitTorrent download task in the NSA’s web configurator screens, you can just 
copy and paste the URL of the torrent file. The NSA automatically downloads the torrent file 
and saves it in a torrent folder located in the same folder where the NSA stores downloaded 
files (the admin share’s download folder by default). 
If you already have the torrent file saved on your computer, you can just specify its location 
when adding a download task through the web configurator. Another method is to use FTP or 
a CIFS program (Windows Explorer for example) to copy the torrent file into the torrent 
folder. The torrent folder is located in the same folder where the NSA stores downloaded files 
(the admin share’s download folder by default). The NSA automatically downloads and uses 
the torrent file. 
After your BitTorrent download and sharing are finished, you can go to the torrent folder and 
delete the .torrent file if you need to free up hard disk space.  
8.5.2  Protecting Your Network and NSA When Using BitTorrent
When you download using BitTorrent, you reveal your IP address. This increases the risk of 
hacking attacks, which can be protected against by a good firewall. 
8.5.2.1  Use a Hardware-based Firewall
Place a hardware-based firewall between your network and the Internet (a software-based 
firewall on your computer would just protect the computer itself, not the NSA since your 
computer is not between your NSA and the Internet). Ideally your firewall should have all of 
the following.