The ASA/PIX Security Appliance comes with a standard set of protocol application inspections. Inspections are functions within the ASA/PIX to ensure that data isn't passing through the ASA/PIX, inside of a packet, that could cause damage to a server or network to which the packet is destined.
Some application inspections have non-security-related features. For example, NetBIOS inspections look into the data portion of the packet at source IP addresses and make sure that those addresses are properly represented in the packet header. All security appliances need this functionality to ensure that network address translation (NAT) functions correctly.
The ASA/PIX performs application inspection for the protocols ...