RADIUS

The Authorization Framework

Moving on in the soup of terminology, we come to the AAA Authorization Framework, an RFC document from the subset of the AAA Working Group set up by the IETF. Like an architecture document, a framework is designed as a roadmap, but it tends to be a bit more specific. Frameworks designate how systems interact with one another, but frameworks generally concentrate more on models specific to certain environments, such as an Internet wholesaler, a corporate VPN center, or other similar situations.

First, though, we should point out the distinctions in terminology. The authorization framework introduces the concept of a User Home Organization (UHO), which is an entity that has a direct contractual relationship with an end user. Also, the Service Provider (SP) is involved, which maintains and provisions the tangible network resources. The UHO and the SP need not be the same organization; a good example of this is, again, an ISP wholesaler or reseller that provides its own network resources to other organizations. For the purposes of this overview, I’ll first look at scenarios in which the UHO and SP are one and the same, and then I’ll cover a more detailed scenario that is commonly found.