Service Provider Challenge

The service providers of today are faced with many new challenges. The way a user is configured or provisioned for dialup access is most likely different than the way a user would be configured or provisioned for Digital Subscriber Line (DSL). AAA can support these differences using the Remote Authentication Dial-In User Service (RADIUS) protocol.

A popular service today that you see frequently is the wireless "hot spot." Many companies place a wireless hot spot in places of business, airports, hotels, and coffee houses. Agreements are made between service providers, and as a benefit to their subscribers, you can use a hot spot in an airport.

Take a look at an example. If you, as a subscriber to Verizon DSL service, for example, were to try to use a hot spot that was owned by another service provider, you would need some way to identify to the owner of the hot spot that you are part of an agreement that allows you to use it. When you connect, you are asked to provide your authentication credentials. You enter your trusty username preceded by some characters that Verizon has instructed you to enter. The authentication is successful, and you are surfing the Net. What happened behind the scenes is a mystery, but as long as you can get online, who really cares, right? The truth is that the service providers care.

When you entered your username that was provided by Verizon, preceded by those characters, you started an authentication request. That authentication request eventually makes it to a server at Verizon that said you were allowed to be online. The preceding characters are possibly defined as a realm in the hot spot owner's AAA server. If your username was VZW/[e-mail], VZW could indicate to the hot spot owner that you are a Verizon customer. This would cause the hot spot owner's AAA server to forward you to a Verizon AAA server where the rest of your username would indicate who you are.

This would make the hot spot owner a broker of sorts. In fact, the person sitting next to you might be a user of SBC services (as opposed to Verizon) and has provided information that forwards their credentials to an SBC AAA server.