Unified threat management (UTM) is a term coined by Charles Kolodgy of International Data Corporation (IDC) in 2004 which is used to describe network firewalls that have many features in one box, including junk e-mail filtering, anti-virus capability, an intrusion detection (or prevention) system (IDS or IPS), and World Wide Web content filtering, along with the traditional activities of a firewall. These are application-layer firewalls that use proxies to process and forward all incoming traffic, though they can still frequently work in a transparent mode that disguises this fact. However, if this uses too much processor time, the higher-level inspection can be disabled so that the firewall functions like a much simpler network address translation (NAT) gateway.
