A reliable network firewall helps protect your business from unauthorized access, while permitting legitimate traffic – and is therefore, an essential component of any size network. However, as organizations continue to evolve and the workforce continues to become increasingly mobile and dynamic in nature, modern-day firewalls must also adapt.
Cisco offers firewalls to match a variety of needs, including:

• For high-speed, data center environments, Cisco ASA 5585-X Adaptive Security Appliances and Cisco Catalyst 6500 Series ASA Services Modules. These products deliver MultiScale performance for maximum connections per second with the lowest overhead

• For edge and campus environments, the Cisco ASA 5520, 5540, and 5550 Adaptive Security Appliances, as well as routers with integrated Cisco IOS Firewall

• For small or branch office environments, integrated firewall and security in the Cisco Integrated Services Router Generation 2, the Cisco ASA 5505 and 5510 Adaptive Security Appliances, as well as the Cisco SA 500 Series Security Appliances

• For virtualized environments, the Cisco Virtual Security Gateway for Nexus 1000V Series Switch

For more Information: http://www.cisco.com/en/US/products/ps5708/Products_Sub_Category_Home.html