This optional subscription adds a customizable and easy-to-use portal-based SSL VPN as well as sophisticated Network Access Control (NAC) functionality and CudaLaunch support. The Barracuda Network Access Client, when used with the F-Series firewall, provides centrally managed Network Access Control (NAC) and an advanced personal firewall. This allows enforcement of minimum Windows client security prerequisites before being allowed access to the network or access to a quarantine network. Security posture can be specified according to available Windows patch level, availability of antivirus and/or anti-spyware, and user ID. Access restrictions are enforced locally on the client by the centrally managed personal Windows firewall as well as at the gateway. Using existing Barracuda CloudGen Firewall appliances, Barracuda Networks offers a ready-to-use Network Access Control framework without expensive investments into the basic network infrastructure.