The Cisco ASA 5520 Adaptive Security Appliance delivers a wide range of security services with Active/Active high availability and Gigabit Ethernet connectivity for medium-sized enterprise networks, in a modular, high performance appliance. Using its four Gigabit Ethernet interfaces and support for up to 25 VLANs, businesses can easily deploy these security services into multiple zones within their network. The Cisco ASA 5520 Adaptive Security Appliance scales with businesses as their network security requirements grow, delivering solid investment protection. Businesses can extend their IPSec and SSL VPN capacity through multiple means to support a larger number of mobile workers, remote sites, and business partners. VPN capacity can be increased by taking advantage of the integrated VPN clustering and load-balancing capabilities of the Cisco ASA 5520 Adaptive Security Appliance, as well as more than doubling each platform's VPN capacity through the installation of a VPN upgrade license.