Updated 1/14/13: Clarifications on update process and Netflix handling
Qualcomm's StreamBoost is automatic network bandwidth management / traffic shaping technology. It is largely based on work by BigFoot Networks, which Qualcomm acquired a few years ago. In a nutshell, the theory behind StreamBoost is that it intelligently manages network bandwidth and latency, giving each application the bandwidth it needs for the best possible user experience.
Since theory is one thing and reality another, we decided to put Qualcomm's claims to the test. My mission was to put StreamBoost through its paces until it broke or I threw in the towel trying.
For StreamBoost to optimally operate, it needs to both send information about your network use and automatically receive updates from its cloud component. You must opt into this update, as shown in the screenshot below.
StreamBoost update opt-in
If you decide not to opt-in, you can still receive updates via manual firmware updates. I followed up with D-Link to get a little more information about the opt-in service. I learned StreamBoost continuously monitors "de-identified" data about application use and data consumption, but not specific content. StreamBoost also captures network diagnostic information to help determine if the streams are acting as they should.
For example, StreamBoost will know how long a Netflix session is open, how much data is consumed and its resolution. But they will not know the specific content you are watching.
The "crowd-sourced" information is intended to continuously improve StreamBoost performance in terms of better application / service detection, improved application policies and better understanding of applications and devices. StreamBoost is also continuously updated to handle new games, devices and services as they are released, even as quickly as within 24 hours of detection.
Right now, updates are coming about every two weeks and there is no way for you to tell your router's update level or even whether an update has occurred. A screen with current update definition is something Qualcomm is considering for a future release, but there are no definite plans at this time. If an update is installed, it will be loaded only after the router is rebooted. But if I don't know whether an update has occurred, how do I know when to reboot? This needs work. In the end, opting into updates sounds like a good thing, if you are going to depend on StreamBoost to keep your network humming along.
Qualcomm clarification: Reboots are absolutely not required to receive updates. When StreamBoost has an update, it generally will take 24-48 hours to be sent down to the entire installed base of routers. If an update is ready, rebooting the router will speed up the process by having the router check with the StreamBoost cloud during boot time.
Getting back to setup, the last thing StreamBoost does is take a sample of your bandwidth so that it knows what it's working with. If you feel inclined to skip the speed test you can always enter upload and download values later. The sample the setup wizard found for my connection fell right in line with what I see at speedtest.net, which you can see in the image below.
WAN speed sampling in the setup wizard
To test StreamBoost, I used test scenarios based on the reviewer's guide D-Link provided. My download bandwidth is 28 Mbps, while upload is just under 6 Mbps. StreamBoost marketing material references a typical home internet connection as around 8 Mbps download and 1 Mbps upload. So D-Link provided a speed limiter to slow my connection down if needed. But I was determined to try Streamboost without the limiter. So all of the following tests were performed without the limiter at my full internet bandwidth.
Regular router - no QoS
I loaded up my first test case on the Edimax BR-6475nd I had used for wireless extender testing. The first round of tests had QoS disabled.
I loaded Team Fortress 2 on a computer sufficienty powerful for gaming and the game's latency meter indicated about 50 ms. I then started a Pandora stream and HD video streams on everything else that I had, which was five other devices. I went back and looked at the latency meter in Team Fortress 2, which was still lingering around 50 ms. The video was playing smoothly everywhere.
I then started uTorrent on a laptop and started downloading five > 1 GB files from the Fedora repository. The latency meter on Team Fortress 2 then jumped to about 300 ms, Netflix looked degraded on the TV and I could not get an HD Vimeo or Vudu video to start. A quick look at the uTorrent screen and it was fairly obvious that uTorrent was taking most of the bandwidth.
Regular router - iQoS enabled (priority-based)
I shut everything down and enabled iQoS on the Edimax router. iQoS is a priority-based Qos that measures usable bandwidth and then lets you prioritize by Media, Game, App, FTP and file download. I set it up with Media having highest priority, followed by gaming and then downloads. I then restarted my test.
As before, I could start as many HD video streams as I wanted and Team Fortress 2 had about a 50 ms latency with downloads not running. I then set uTorrent loose with the five large downloads. One video started buffering and latency in Team Fortress 2 jumped to about 120 ms (still better than the 300 ms without QoS).
I tried running HD Vimeo on the TV and could not and Netflix also appeared degraded. Samsung's "Smart Hub" on the TV timed out before I could even get to Vudu. I tried to open a web browser on one computer and it just hung. Edimax' QoS was doing something, but my WAN was at its knees. A quick look at uTorrent showed lots of bandwidth going to downloads, despite being prioritized third.