RADIUS

Realms

While RADIUS can be as ignorant of externalities as an administrator wants, it can also be made aware of various implementations. RADIUS is flexible with regard to various design schemes to allow it to support different business and infrastructure models. Take, for instance, a cooperative agreement among three regional Internet service providers. Let’s explore this example in greater detail.

Northwest Internet serves the northern and western portions of a state. Southeast Internet serves the southern and eastern regions, and Central State Internet provides support to the central area of a state. While each of these ISPs may have modem-pool resources in overlapping geographical areas, most of the access resources are confined to particular regions.

Now, each of the service providers determine that there is sufficient demand to offer a roaming service to customers to allow them to dial a local number anywhere in the state to access the Internet. While the service would be more expensive than normal, with a home-area dial-up service, a local number allows the customer to avoid expensive long-distance charges most hotels and other lodging establishments levy. Each ISP determines that it’s not fiscally efficient for them to construct points of presence in each region, so they form a cooperative alliance in which each ISP allows the other two ISPs to have access to their respective modem pools. So Northwest Internet can offer a roaming service to its mobile users who happen ...