New: Check out OneSwarm, our new, privacy-preserving P2P software release.
BitTyrant is a new, protocol compatible BitTorrent client that is optimized for fast download performance. BitTyrant is...
For details about these claims, check out the information below.
No. BitTyrant does not change the amount of data uploaded, just which peers receive that data. Specifically, peers which upload more to you get more of your bandwidth. When all peers use the BitTyrant client as released, performance improves for the entire swarm. The details of this are explained further below. In our paper, we consider situations in which peers use clients which attempt to both maximize performance and conserve upload contribution, but BitTyrant, as released, attempts only to maximize performance.
BitTyrant differs from existing clients in its selection of which peers to unchoke and send rates to unchoked peers. Suppose your upload capacity is 50 KBps. If you’ve unchoked 5 peers, existing clients will send each peer 10 KBps, independent of the rate each is sending to you. In contrast, BitTyrant will rank all peers by their receive / sent ratios, preferentially unchoking those peers with high ratios. For example, a peer sending data to you at 20 KBps and receiving data from you at 10 KBps will have a ratio of 2, and would be unchoked before unchoking someone uploading at 10 KBps (ratio 1). Further, BitTyrant dynamically adjusts its send rate, giving more data to peers that can and do upload quickly and reducing send rates to others.
Yes. Although the evaluation in our paper focuses on users with slightly higher upload capacity than is typically available from US cable / DSL providers today, BitTyrant’s intelligent unchoking and rate selection still improves performance for users with less capacity. All users, regardless of capacity, benefit from using BitTyrant.
This is a subtle question and is treated most thoroughly in the paper. The short answer is: maybe. A big difference between BitTyrant and existing BitTorrent clients is that BitTyrant can detect when additional upload contribution is unlikely to improve performance. If a client were truly selfish, it might opt to withhold excess capacity, reducing performance for other users that would have received it. However, our current BitTyrant implementation always contributes excess capacity, even when it might not improve performance. Our goal is to improve performance, not minimize upload contribution.
Download peer information with per-connection ratios and BitTyrant status.
Note: BitTyrant is research software. Although we have used it internally for several months, it is likely to still have several bugs and performance quirks that we have not yet identified. If you’ve found a bug, please send us a note.
BitTyrant requires Java 1.5. If you're having problems getting things started, try updating your JVM.
Important: For BitTyrant to be most effective, it is crucial that you accurately set your upload capacity during configuration.
Version: 1.1.1 (Released 7 September, 2007) (changelog)
 |
Mac OS X disk image (Req. 10.4) | MD5: 422de23cc335ffb1086e30329e337cde |
 |
Windows installer | MD5: d7741898dcb73a5d600d797fc56f4dc4 |
 |
32-bit Linux JAR and Installation instructions | MD5: 44a65aa40d8a3e3aa2e90452522ec679 |
|
|
64-bit Linux JAR | MD5: eafa51b8d6ee0c0f3309c738f1a63142 |
The BitTyrant source code is also available. Anonymous trace data collected during our study is available by request.
A poster and talk regarding BitTyrant were presented in the 2006 UW CSE Affiliates meeting.
| Graduate students | Undergraduates | Faculty |
| Michael Piatek | Jarret Falkner | Tom Anderson |
| Tomas Isdal | Arvind Krishnamurthy | |
| Arun Venkataramani |
 |
BitTyrant is based on modifications to the Azureus 2.5 code base. |
 |
Initial testing of BitTyrant was conducted on the Emulab testbed. |
 |
BitTyrant’s wide-area evaluation was performed using the PlanetLab testbed. |
 |
The BitTyrant software distribution is mirrored using the CoBlitz file distribution service. |