Dial-in user authentication should be as simple as it sounds. While the RADIUS (Remote Authentication Dial-In User Service) protocol is an open standard for authentication, access control (authorization) and accounting, the service behind the protocol is what matters. In addition to supporting all the aspects of the protocol, a good RADIUS server offers multiple options for back-end authentication, supports external databases for user entries and accounting data, and provides fine-grained control over every authentication request.

With its support for various back-end authentication sources including Novell Bindery, NDS, NT Domains and Unix, Shiva Corp.'s Access Manager allows dial-in authentication for most common user directories. In addition, support for the RADIUS proxy protocol enables a single RADIUS server to redirect authentication requests to any number of additional target RADIUS servers on the back end, letting users choose authentication sources on the fly.

We also were impressed by Access Manager's conditional authentication features, such as limiting dial-in access based on time of day, maintaining and enforcing usage quotas, and providing session configurations based on individual users, groups or other factors.

Shiva Access Manager 3.0, $3,000 to 4,000,
Shiva Corp.,
(800) 97-SHIVA, (781) 687-1000.
www.shiva.com