KEY UTM FEATURES EXPLAINED

Unlike standard firewall routers, UTM appliances vary widely in their features and capabilities--and for the most part, you get what you pay for. Here are the major features to look for when choosing a network security package for your small business.

By stopping viruses and malware at the Internet gateway, you can reduce the burden on individual computers and prevent most threats from reaching your network. Antivirus tools also provide a second layer of protection beyond your individual PCs' virus checkers, which frustrated users may disable and negligent users may update too infrequently. Gateway checkers can't find every piece of malware, however, because they lack the horsepower needed to emulate the programs on each computer. Thus you should retain the virus and spyware tools on each PC.

It's also worth finding out the brand of virus or malware checker that the UTM appliances you are considering use. Some devices work with their own software, but most rely on third-party tools from companies such as McAfee, Kaspersky, or even ClamAV (the open-source option). You should make sure that ongoing support will be available.

With content and keyword filtering, you can block access to specific IP addresses, domains, and URLs by invoking the vendor's database of inappropriate Web sites and keywords in various categories, as well as by adding or subtracting your own. Content filtering isn't just for porn. You could block Web mail sites, for example, or video-streaming services. You can use filtering on outgoing data as well as incoming data, so you could prevent people within your network from sending explicit e-mail or instant messages. Check to confirm that the UTM appliances you're considering have the content-filtering capabilities you need.

A few UTM appliances have antispam filters, but most offer it only as an extra-cost option (if at all). Because spam filtering can have a major effect on firewall throughput, many IT experts prefer to use a separate spam filter at the mail server. Your ISP probably can perform this task at little or no extra charge if you use its e-mail services. If you run your own e-mail server behind your firewall, UTM appliance-based spam filtering may be appropriate.