radius, r (noun)

the length of a line segment between the center and circumference of a circle or sphere

radius (noun)

a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere)

radius (noun)

a circular region whose area is indicated by the length of its radius

"they located it within a radius of 2 miles"

radius (noun)

the outer and slightly shorter of the two bones of the human forearm

spoke, wheel spoke, radius (noun)

support consisting of a radial member of a wheel joining the hub to the rim

radius (Noun)

The long bone in the forearm, on the side of the thumb.

radius (Noun)

The lighter bone (or fused portion of bone) in the forelimb of an animal.

radius (Noun)

A line segment between any point on the circumference of a circle and its center/centre.

radius (Noun)

The length of this line segment.

RADIUS

Remote Authentication Dial In User Service is a networking protocol that provides centralized Authentication, Authorization, and Accounting management for computers that connect and use a network service. RADIUS was developed by Livingston Enterprises, Inc. in 1991 as an access server authentication and accounting protocol and later brought into the Internet Engineering Task Force standards. Because of the broad support and the ubiquitous nature of the RADIUS protocol, it is often used by ISPs and enterprises to manage access to the Internet or internal networks, wireless networks, and integrated e-mail services. These networks may incorporate modems, DSL, access points, VPNs, network ports, web servers, etc. RADIUS is a client/server protocol that runs in the application layer, using UDP as transport. The Remote Access Server, the Virtual Private Network server, the Network switch with port-based authentication, and the Network Access Server, are all gateways that control access to the network, and all have a RADIUS client component that communicates with the RADIUS server. The RADIUS server is usually a background process running on a UNIX or Microsoft Windows server. RADIUS serves three functions:

RADIUS

Remote Authentication Dial-In User Service (RADIUS) is a networking protocol that provides centralized authentication, authorization, and accounting (AAA) management for users who connect and use a network service. RADIUS was developed by Livingston Enterprises in 1991 as an access server authentication and accounting protocol. It was later brought into IEEE 802 and IETF standards. RADIUS is a client/server protocol that runs in the application layer, and can use either TCP or UDP. Network access servers, which control access to a network, usually contain a RADIUS client component that communicates with the RADIUS server. RADIUS is often the back-end of choice for 802.1X authentication. A RADIUS server is usually a background process running on UNIX or Microsoft Windows.