We got some excellent feedback after yesterday’s announcement, but there were a lot of people asking exactly how we speed up your iTunes downloads. The short answer is that we make multiple, parallel connections back to the iTunes music store for each download.
A single TCP connection, no matter how wide the pipe, hits startlingly low theoretical throughput limits with just a little bit of packet loss or latency. Creating multiple connections back to iTunes allows Autobahn to overcome those limitations and allow your downloads to approach the inbound maximum on your last mile.
Creating multiple connections does not increase the total bandwidth load on Apple, it just condenses one user’s same number of downloaded bytes into a narrower time window. Even if everyone downloading from iTunes used Autobahn Accelerator, Apple wouldn’t spend a penny more on bandwidth rate in Gbps wouldn’t increase. We’re able to accelerate iTunes downloads without any server side support because they were already 100% standard HTTP.
As to who should expect to see acceleration, the short answer is: everyone. International and high latency users can see dramatic improvement — with these techniques we’ve seen as fast as 30x increases for some locations in Australia. WiFi can also be a considerable contributor to packet loss and latency. You’re going to get the best performance with Autobahn on a wired connection, but this will also improve performance over wireless noticeably.
July 9th, 2007 at 9:43 pm
Ry4an,
Jay Wyant from the past here - good to see you are doing well. Was telling a co-worker about Swarmcast, and saw the accelerator. Two questions: 1) if this is optimized for iTunes, does that mean you have some code on their end to make this work? 2) If so, then what do we have to do to get that code on other sites? I use video relay to make phone calls, and this gizmo could well help generate clearer pictures between me and the interpreter.
July 10th, 2007 at 12:55 am
Hi, Jay, great to hear from you again. We don’t have anything special on the iTunes side of things. Instead of use our knowledge of their server setup to optimize downloads from the client side. We can bring Autobahn to bear on any site, but understandably are focusing on those with a lot of user traffic. If you’ve got a site that’s getting a great many viewers contact info@getautobahn.com to suggest it. Otherwise, we’ll soon be releasing instructions on how anyone can accelerate their site without us having to tailor an accelerator to it.
July 11th, 2007 at 1:35 pm
Ry4an,
Thanks. We receive a lot of videos from clients as part of our work. It would be interesting to see if we can speed up delivery speeds without increasing bandwidth. I imagine one dependency is how many connections we have from the internet to our servers.
October 10th, 2007 at 4:47 am
Why does autobahn seem to be slowing down my download? I read on the other post that you guys downloaded a 1GB movie in nine minutes. Mine is half that, and it is still slower than ever. Any clue why?
October 12th, 2007 at 8:07 pm
Mr. Treez,
Thanks for your comment. Your experience might be due to a misconfiguration. For future reference, the best place to seek help is in the forums, where our engineers hang out to help folks. I’ve copied your note onto the forums, so look for communication there. We look forward to helping out.
Best,
John
October 15th, 2007 at 5:27 pm
pinetreez, John copied your question into the forum here: http://forum.getautobahn.com/vanilla/comments.php?DiscussionID=9 Come on over and we’ll figure this out.
February 22nd, 2008 at 5:15 pm
[...] Autobahn, an accelerator for iTunes which can speed download times by up to 90%, and is up to 30 times faster in high latency areas such as Australia. Swarmcast works with content providers like MLB to enhance [...]