Fast proxy server; can use all of the major vendor's URL databases.
Not as flexible or as easy to manage as a dedicated appliance.
If you're looking to replace proxy servers and introduce web filtering, the ProxySG 200 is a good all-in-one choice.
The smallest appliance on test, Blue Coat's ProxySG 200 is half the width of standard rack mount equipment and uses a notebook-style power supply. Rather than a pure web filtering appliance, the ProxySG 200 is a full-fledged web proxy, with URL filtering built in. This makes it quick to process requests and gives you a single point of management for your proxy and web filtering.
Management is done through a Java application that sits on the appliance. We did, however, have a little trouble finding it. The provided CD doesn't have any documentation on it, just a link to the website. However, there wasn't any ProxySG 200-specific documentation available, when the ProxySG 400 and above all have quickstart guides. Fortunately, our 200 came with a paper guide.
Once into the management console you need to choose a filtering database. ProxySG supports manually entered local databases, Blue Coat's own, SurfControl, WebSense, Proventia and others.
Provided you buy the correct license key you can choose which one you want to install. However, all you're paying for is the URL database, not the management. All management is performed through the Visual Policy Editor.
It is quite easy to use and you can choose to block websites by the categories listed in the URL database. There are the standard options, too, including choosing user groups and times rules. It is not quite as simple as, say, SurfControl's interface, but it covers all of the bases. We managed to configure ours to block our test websites and deny our HTTP-Tunnel software as well.
As this is a full web proxy, it has support for all the major protocols including HTTP, Socks and FTP. You can configure the ProxySG 200 to block P2P traffic and there's full policy-based bandwidth limitation.
With proxies to suit different network sizes, the ProxySG is an accomplished product that can use the filtering database of your choice. But for those networks that already have proxy servers set up, you are probably better off with a dedicated web-filtering appliance, or software.