GCN LAB REVIEW
Cruise control for TCP
FastSoft E 10 optimizes transfer times, especially for large files
- By Greg Crowe
- Apr 06, 2009
Data center administrators are always looking for ways to accelerate throughput so they can get data to users faster. Unfortunately, many approaches require some sort of installation on the client end, which can be especially annoying if one of the installations goes badly.
FastSoft has a way around that problem. The company’s E-series Internet Accelerators can significantly decrease file-transfer times on the server end with no client-side installation required.
FastSoft does this by optimizing the TCP layer, which is used in pretty much every piece of traffic on the Internet. When left to its own devices, TCP uses an algorithm called additive increase/multiplicative decrease (AIMD), which pushes the limits of the available bandwidth by increasing the packet rate in small intervals until it starts losing packets. At that point, it drops its rate significantly — sometimes by half — and then starts the slow build all over again. You might not notice a difference with small files, but transfer times for large files can be affected considerably.
FastSoft developed FastTCP, which adjusts the flow of TCP packets by maintaining an optimal rate for most of the transfer. The larger the files being transferred, the more the technology tends to shine. And it works for every computer attached to a network that has a FastSoft E 10 appliance on the front end.
To better understand the difference between the two methods, imagine you’re driving a car. With AIMD, the only two options for speed control are pressing the gas pedal all the way down or taking your foot off it entirely. The car’s speed will increase until there is a chance of crashing because you are going too fast, then it will drop significantly because you have to take your foot off the gas. With FastTCP, you are able to control how much you use the gas pedal, and you can cruise at a speed just under the threshold at which you’d have problems.
The FastSoft E 10 system uses two appliances that each take up 1U of rackmount space. The E Series is a 22-inch-deep server that does the work of the accelerator device. The Bypass Unit is attached to a 1U plate but is only about as big as an optical drive. Because the system is situated between the router and the rest of the network, the Bypass Unit is designed to allow access even if the E Series unit should lose power or experience other problems.
Although we agree this is an essential part of any in-line system, we don’t understand why the Bypass Unit wasn’t integrated into the other device, especially because it looks like there’s enough room in the server box. It seems like a waste of a 1U spot, and it could put a strain on a network’s available rack space.
However, the FastSoft system was easy to deploy. We just set a computer’s network adapter to the same subnet as the E Series, connected it to the management port and opened a browser to its IP number. Then it was a matter of hooking up the Bypass Unit between the router and the rest of the network and connecting the E Series unit to it, and we were ready to access it via the network to enter licensing information and turn on the accelerator.
We installed a File Transfer Protocol server program on one of the servers in our test network and timed file transfers to a computer outside the network running an FTP client. Because we knew that we’d only see significant improvement in transfer speeds for larger files, we started with an 80M graphics file as our baseline. We transferred it from the server to the client several times with the acceleration option of the E 10 turned off and on in order to get a good average for each method.
The result was a 23 percent reduction in file transfer times when the acceleration was switched on. With a 750M video file, the improvement increased to 47 percent. From this we concluded that relative transfer times would continue to improve as the file size increased. Also, we theorized that in a more closed system in which the clients’ environment and settings were more optimally maintained, the improvement could be even greater.
The FastSoft E 10 has a government price of $9,995 — a good deal for a device that can handle up to 10 megabits/sec of throughput and shows noticeable improvement in transfer rates via regular TCP. For larger networks, FastSoft has accelerators that can handle up to 1 gigabit/sec of throughput. For data center administrators who want to move files faster without installing anything on the client side, the FastSoft E-series might be just what they need.
FastSoft, 626-357-7012, www.fastsoft.com
Greg Crowe is a former GCN staff writer who covered mobile technology.