An Extreme BitTorrent Test Case

Bill Malchisky  September 17 2012 03:00:00 AM

Let me describe an unexpected test of BitTorrent performed over UKLUG travels, which further strengthened my respect for BitTorrent as a technology. All major desktops offer BitTorrent clients, for acquiring large downloads in an efficient manner. For those that are unfamiliar, BitTorrent allows for the ability to borrow bandwidth from many locations in parallel, while properly assembling your target file efficiently on your local system. Run a MD5 calculation and you can easily verify the file's integrity. This file sharing process is nothing new, due to BitTorrent's popularity, but it provides a solid implementation. The ability to pause and restart later is a strong benefit too. Being a scientist, I was curious with how things would progress when this concept was tested further.

Test Supposition
What happens if you pause a download, travel to a different country, a day later change NICs, change LAN protocols, change networks, then continue the process?

Process
I started to pull down a Linux DVD ISO before my shuttle arrived  to the airport recently. Unfortunately, the download was taking longer than anticipated and I only acquired 34% of the file. Rather than risk missing my flight, I paused -- rather than quit -- the download process. I then went to the airport and thought I would try again there. Security queue delays made the download continuation an impossibility. Off to London I went. Nine hours later I arrived at the airport lounge, needing to get some work done. I fired-up the laptop, connected to the lounge's WiFi network. Only a few people were in the lounge, so I thought I would attempt to finish the transfer.

Results
Sure enough, I continued the download and it worked. Without missing a beat --- or a byte --- BitTorrent immediately pulled the ISO image. Just :45 minutes later it finished. I ran an MD5 sum calculation and it came back perfect. In the end, I introduced approximately a 14 hour total break, plus changing the following three variables: networks, NICs, and continents. I did not reboot, but hibernated my laptop with each use during the download pause.

Synopsis
BitTorrent did not care at all with the changes. Zero complaints from the client tool, I was then able to install my new VM and run the desired tests. This saved me a lot of time. It is certainly good to know that one can interrupt a download in that manner, without impact. Few technologies allow such an interruption in file access approaches. If the site to client access is one-to-one direct, it may seem less remarkable to you, excepting the time-out as many sites will close the connection well before 14 hours elapses. For me, having seen many download sites or file transmissions time-out within :30, the these BitTorrent results were well received. As I dislike wasting time, their solid algorithm is quite appealing to me.


In the end, BitTorrent is a great technology, now in it's 11th year (as of this writing). If you aren't using this technology for large file transfers, consider it. Many reputable sites that work with BitTorrent offer the torrent files right there -- which increases the trustworthiness of the process (if one is concerned about malware).

BitTorrent main forum site
Popular Clients
Linux - due to its roots as a pure network operating system, there are several great clients; so feel free to experiment: Deluge, qBittorrent, KTorrent (KDE), Transmission,  rTorrent (terminal)
Mac -- Transmission
Windows -- uTorrent

Linux Client Notations

• uTorrent is available as a server for Linux and runs in a terminal as a client
• Transmission on Linux offers fewer features than the Mac variety where it excels; but the GTK+ variety appears to work well on Ubuntu
• Deluge and qBittorrent are the more robust client BitTorrent flavors: the former offers several plugins for heavy BitTorrent users -- e.g. remote torrent monitoring via a mobile device, bandwidth usage control, RSS feed downloads, and encryption; the latter is more lightweight and has more built-in features

Stay productive my friends.

• Comments [0]