Network Access Control Systems
A traditional network access server (NAS) is a server that performs authentication and authorization functions for potential users by verifying logon information. In addition to these functions, NAC restricts the data that each particular user can access, as well as implementing anti-threat applications such as firewalls, antivirus software and spyware-detection programs. NAC also regulates and restricts the things individual subscribers can do once they are connected. Several major networking and IT vendors have introduced NAC products.
NAC is ideal for corporations and agencies where the user environment can be rigidly controlled. However, some administrators have expressed doubt about the practicality of NAC deployment in networks with large numbers of diverse users and devices, the nature of which constantly change. An example is a network for a large university with multiple departments, numerous access point s and thousands of users with various backgrounds and objectives.