What Is Burstable Bandwidth? Five Points to Consider


Internet Bursting

Internet Providers continually use clever marketing analogies to tout their burstable high-speed Internet connections. One of my favorites is the comparison to an automobile with overdrive that at the touch of button can burn up the road. At first, the analogies seem valid, but there are usually some basic pitfalls and unresolved issues.  Below are five points that are designed to make you ponder just what you’re getting with your burstable Internet connection, and may ultimately call some of these analogies, and burstable Internet speeds altogether, into question.

  1. The car acceleration analogy just doesn’t work.

    First, you don’t share your car’s engine with other users when you’re driving.  Whatever the engine has to offer is yours for the taking when you press down on the throttle.  As you know, you do share your Internet connection with many other users.  Second, with your Internet connection, unless there is a magic button next to your router, you don’t have the ability to increase your speed on command.  Instead, Internet bursting is a mysterious feature that only your provider can dole out when they deem appropriate.  You have no control over the timing.

  2. Since you don’t have the ability to decide when you can be granted the extra power, how does your provider decide when to turn up your burst speed?

    Most providers do not share details on how they implement bursting policies, but here is an educated guess – based on years of experience helping providers enforce various policies regarding Internet line speeds.  I suspect your provider watches your bandwidth consumption and lets you pop up to your full burst speed, typically 10 megabits, for a few seconds at a time.  If you continue to use the full 10 megabits for more than a few seconds, they likely will reign you back down to your normal committed rate (typically 1 megabit). Please note this is just an example from my experience and may not reflect your provider’s actual policy.

  3. Above, I mentioned a few seconds for a burst, but just how long does a typical burst last?

    If you were watching a bandwidth-intensive HD video for an hour or more, for example, could you sustain adequate line speed to finish the video? A burst of a few seconds will suffice to make a Web page load in 1/8 of a second instead of perhaps the normal 3/4 of a second. While this might be impressive to a degree, when it comes to watching an hour-long video, this might eclipse your baseline speed. So, if you’re watching a movie or doing any another sustained bandwidth-intensive activity, it is unlikely you will be able to benefit from any sort of bursting technology.

  4. Why doesn’t my provider let me have the burst speed all of the time?

    The obvious answer is that if they did,  it would not be a burst, so it must somehow be limited in some duration.  A better answer is that your provider has peaks and valleys in their available bandwidth during the day, and the higher speed of a burst cannot be delivered consistently.  Therefore, it’s better to leave bursting as a nebulous marketing term rather than a clearly defined entity.  One other note is that if you only get bursting during your provider’s Internet “valleys”, it may not help you at all, as the time of day may be no where near your busy hour time, and so although it will not hurt you, it will not help much either.

  5. When are the likely provider peak times where my burst is compromised?

    Slower service and the inability to burst are most likely occurring during times when everybody else on the Internet is watching movies — during the early evening.  Again, if this is your busy hour, just when you could really use bursting, it is not available to you.

These five points should give you a good idea of the multiple questions and issues that need to be considered when weighing the viability and value of burstable Internet speeds.  Of course, a final decision on bursting will ultimately depend on your specific circumstances.  For further related reading on the subject, we suggest you visit our articles How Much YouTube Can the Internet Handle and Field Guide to Contention Ratios.

Burstable Internet Connections — Are They of Any Value?

A burstable Internet connection conjures up the image of a super-charged Internet reserve, available at your discretion during a moment of need, like pushing the gas pedal to the floor to pass an RV on a steep grade. Americans find comfort knowing that they have that extra horsepower at their disposal. The promise of power is ingrained in our psyche, and is easily tapped into when marketing an Internet service. However, if you stop for a minute, and think about what is a bandwidth burst, it might not be a feature worth paying for in reality.

Here are some key questions to consider:

  • Is a burst one second, 10 seconds, or 10 hours at a time? This might seem like a stupid question, but it is at the heart of the issue. What good is a 1-second burst if you are watching a 20-minute movie?
  • If it is 10 seconds, then how long do I need to wait before it becomes available again?
  • Is it available all of the time, or just when my upstream provider(s) circuits are not busy?
  • And overall, is the burst really worth paying for? Suppose the electric company told you that you had a burstable electric connection or that your water pressure fluctuated up for a few seconds randomly throughout the day? Is that a feature worth paying for? Just because it’s offered doesn’t necessarily mean it’s needed or even that advantageous.

While the answers to each of these questions will ultimately depend on the circumstances, they all serve to point out a potential fallacy in the case for burstable Internet speeds: The problem with bursting and the way it is marketed is that it can be a meaningless statement without a precise definition. Perhaps there are providers out there that lay out exact definitions for a burstable connection, and abide by those terms. Even then we could argue that the value of the burst is limited.

What we have seen in practice is that most burstable Internet connections are unpredictable and simply confuse and annoy customers. Unlike the turbo charger in your car, you have no control over when you can burst and when you can’t. What sounded good in the marketing literature may have little practical value without a clear contract of availability.

Therefore, to ensure that burstable Internet speeds really will work to your advantage, it’s important to ask the questions mentioned above. Otherwise, it very well may just serve as a marketing ploy or extra cost with no real payoff in application.

Update: October 1, 2009

Today a user group published a bill of rights in order to nail ISPs down on what exactly they are providing in their service contracts.
ISP claims of bandwidth speed.

I noticed that  in the article, the bill of rights, requires a full disclosure about the speed of the providers link to the consumers modem. I am not sure if this is enough to accomplish a fixed minimus speed to the consumer.  You see, a provider could then quite easily oversell the capacity on their swtiching point. The point where they hook up to a backbone of other providers.  You can not completely regulate speed across the Internet, since by design providers hand off or exchange traffic with other providers.  Your provider cannot control the speed of your connection once it is off their network.

Posted by Eli Riles, VP of sales www.netequalizer.com.

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