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Tech Talk

The next in our series on the current buzz word – VSAT.

 

A Dish and Chips :

The Ultimate Saucy Solution?

So far we have discussed what a VSAT actually is, what importance a high powered BUC has and why it’s important to have the biggest dish you can afford.

Let’s briefly recap these points. VSAT stands for Very Small Aperture Terminal. A BUC is a Boost Up Converter that takes the signal from the Indoor Unit part of the VSAT and up converts the frequency for transmission over the dish up to the satellite. A BUC also functions as an amplifier. The sum total of the power of the signal that is transmitted is a combination of BUC power and dish size. The bigger the dish and the more powerful the BUC, the faster data rates you can use to upload or transmit back to the satellite.

As important as the Out Door Unit part (ODU) of the system is, the IDU or In Door Unit is even more important. It is very important to select an IDU that meets your requirements. Not all IDU’s are created equal! Buyer Beware!!

IDU’s will fall into one of two categories. These are, 1/ Satellite Modems built on old modem technologies and 2/ Satellite Routers built on the latest Router Technologies. Routers are superior to modems! One very important aspect of using an IDU built on Router technology is QOS or Quality Of Service. QOS is important because this allows the satellite Router to be setup to prioritise the different types of traffic that will be passing over the VSAT. This becomes crucial for things like Skype and VoIP and other real time applications like Video Conferencing. By having QOS at our disposal we can tell the IDU to give Voice Over IP precedence over HTTP (web browsing). This means that when a telephone call is in progress over the VSAT, the web browsing will be given a lower priority then the telephone call going on. This allows the telephone call to have enough bandwidth to allow a clear, stutter free conversation and if you have enough bandwidth the call can be every bit as good as a British Telecom line! (At lower then British Telecom call charges we might add). While the telephone call is in progress, QOS allows web browsing to continue, but at a slower rate because bandwidth is allocated to the telephone call first and anything left over is given to the web browsing application.

QOS is a very powerful feature and allows you to setup your IDU router according to your priorities. For example, you may need email to have a higher priority then web browsing or perhaps you need FTP file transfers or even VPN usage to be the first applications to get the lion’s share of the available bandwidth. QOS allows all this and a lot more. There are also technical implications that are very desirable to have and QOS allows these. If we have gone on and on about QOS it’s because it’s a very desirable thing to have. We cannot overstate the importance of buying into the latest quality equipment that has QOS built into it. It will stand you in good stead and serve you well for years to come with your VSAT. Is there any point in buying into low end technology that has had its day and is now on the way out? When it comes to VSAT, make sure you specify a Satellite Router and make sure QOS is built into that router.