Does Your School Have Enough Bandwidth for On-line Testing?


K-12 schools are all rapidly moving toward “one-for-one” programs, where every student has a computer, usually a laptop. Couple this with standardized, cloud-based testing services, and you have the potential for an Internet gridlock during the testing periods. Some of the common questions we hear are:

How will all of these students using the cloud affect our internet resource?

Will there be enough bandwidth for all of those students using on-line testing?

What type of QoS should we deploy, or should we buy more bandwidth?

The good news is that most cloud testing services are designed with a fairly modest bandwidth footprint.

For example, a student connection to a cloud testing application will average around 150kbs (kilo-bits per second).

In a perfect world, a 40 megabit link could handle about 400 students simultaneously doing on-line testing as long as there was no other major traffic.

On the other hand, a video stream may average 1500kbs or more.

A raw download, such as an iOS update, may take as much as 15,000kbs, that is 100 times more bandwidth than the student taking an on-line test.

A common belief when choosing a bandwidth controller to support on-line testing is to find a tool which will specifically identify the on-line testing service and the non-essential applications, thus allowing the IT staff at the school to make adjustments giving the testing a higher priority (QoS). Yes, this strategy seems logical but there are several drawbacks:

  • It does require a fairly sophisticated form of bandwidth control and can be fairly labor intensive and expensive.
  • Much of the public Internet traffic may be encrypted or tunneled, and hard to identify.
  • Another complication trying to give Internet traffic traditional priority is that a typical router cannot give priority to incoming traffic, and most of the test traffic is incoming (from the outside in). We detailed this phenomenon in our post about QoS and the Internet.

The key is not to make the problem more complicated than it needs to be. If you just look at the footprint of the streams coming into the testing facility, you can assume, from our observation, that all streams of 150kbs are of a higher priority than the larger streams, and simply throttle the larger streams. Doing so will insure there is enough bandwidth for the testing service connections to the students. The easiest way to do this is with a heuristic-based bandwidth controller, a class of bandwidth shapers that dynamically give priority to smaller streams by slowing down larger streams.

The other option is to purchase more bandwidth, or in some cases a combination of more bandwidth and a heuristic-based bandwidth controller, to be safe.

Please contact us for a more in-depth discussion of options.

For more information on cloud usage in K-12 schools, check out these posts:

Schools View Cloud Infrastructure as a Viable Option

K-12 Education is Moving to the Cloud

For more information on Bandwidth Usage by Cloud systems, check out this article:

Know Your Bandwidth Needs: Is Your Network Capacity Big Enough for Cloud Computing?

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