Adaptive Security Algorithm
The ASA is an algorithm used by the Cisco Security Appliance to provide better security than
packet filters and better performance than application proxies. Each interface of the firewall
is assigned a security level. Traffic flows through the firewall are managed by the security
level combined with ACLs or conduits. TCP sequence numbers for outbound connections are
randomly generated by the Cisco Security Appliance to greatly reduce the chances of an
inbound TCP session being hijacked.