VPN-1 is a firewall and VPN product developed by Check Point Software Technologies Ltd.
VPN-1 is a stateful firewall which also filters traffic by inspecting the application layer. It was the first commercially available software firewall to use stateful inspection. Later (1997), Check Point registered U.S. Patent # 5,606,668A[1] on their security technology that, among other features, included stateful inspection.[2][3][4] VPN-1 functionality is currently bundled within all the Check Point's perimeter security products. The product, previously known as FireWall-1, is now sold as an integrated firewall and VPN solution.