UTM systems have multiple features and capabilities, including intrusion detection and prevention, , e-mail spam filtering and Web content filtering, as well as the traditional functions of a firewall, integrated into one product offering.

Some vendors offer the option of purchasing UTM appliances for all of the various functions available or integrating just a few of the functions as needed.

It's a fast-growing market. Research firm IDC (a sister company to CSO) released a report in October 2008 saying that it expects UTM products, which passed the $1 billion mark in market size in 2007, will make up 33.6 percent of the total network security market by 2012.

The UTM market has attracted a large number of vendors. Among the market leaders are Fortinet, Cisco, SonicWALL, Juniper, Secure Computing, Check Point, Watchguard, Crossbeam Systems and Astaro.

Vendors continue to add new features to the basic functionality of the products. For example, the latest version of Astaro's Security Gateway product includes HTTPS Proxy Filtering, which allows users to filter and control secure Web traffic and block programs that attempt to bypass security policy with SSL tunneling.