Bandwidth Hoggin'

04/04/2008 13:25

Two of the most often overlooked aspects of network security are those of reliability and availability...

Do you know how much usable bandwidth you have to the internet? Bandwidth is the amount of data you can upload or download through your internet connection. USABLE bandwidth is the amount of data you can upload or download right now: with all of your email, web browsing, downloads and other communications traffic running across it.

We've recently encountered a couple of situations where the usable bandwidth was so small that email was not coming in and users couldn't open web pages. The culprit? Internet Hogs! Specifically, streaming music and video web sites.

Think of bandwidth as a pipe with water flowing through it: the larger the pipe, the more water can fit through. However, even the largest pipe can be useless to you if the water coming through it is being used by something else. Just think about how your shower performs with both the washing machine and dishwasher running.

When you connect to a web site, your computer creates a session with that web server, and the two send information back and forth across the internet connection. Your computer sends up the request for a song and the music web sites send the music in a stream down to your computer. The quality of the music depends on how much data about the music is being sent. A decent quality music stream will send at 128 KBs (Kilobits per second) or about .128 MBs (Megabits per second) down to your computer.

Ponder this: a T1 line, the gold standard in internet connectivity up until a few years ago, has a pipe of about 1.544 MBs to the internet. If you have 12 people listening to music, 12 x .128=1.536 … leaving everyone else in the office to share a whopping .008 MBs. That would equate to a leaky faucet in terms of a pipe.

And that's just music. When we start looking at video streams from sites like YouTube.com, or even CNN.com, the bandwidth usage per person, at minimum, more than doubles. A streaming video in a small window (320x240 pixels) is 300 KBs. Multiply that by a few users and suddenly you have issues.

So, why do people listen to music and watch clips over the internet? Let's face it, it's entertaining, and most likely, they just don't know if it's causing an issue. What does your Internet Usage Policy say? The first step in resolving or heading off issues like this should be to make sure the people affected are aware of the issue and more importantly, what they should be doing.

If you find that the business polices are not effective enough, or you want to make sure this isn’t a problem, there are security products that can block most of these sites or stop the stream before it comes in. In fact, you may already own these products and not even know it…