Celestix MSA Security Appliances enable branch offices to communicate securely with the main office over the internet.

VPN Gateway functionality in Celestix MSA Security Appliances enables an administrator to join entire networks together through VPN site-to-site links-e.g. connecting an organization's main and branch offices to each other.

The Internet Protocol security (IPSec) tunnel mode VPN router feature in Celestix MSA Security Appliances enables the firewall administrator to set strong access controls, including user, group, site, computer, protocol, and application-layer-specific controls over traffic moving through the site-to-site link. With these controls in place, users on the local network can access only allowed content on the remote network, and remote network users can access only the designated local network resources.

Figure 1 illustrates how Celestix MSA Security Appliances and ISA Server 2004 help provide secure connections between branch offices and the main office.