When a subscriber calls into its Internet Service Provider (ISP), a
central office receiving the call is triggered to perform a Local Number
Portability (LNP) query. This LNP query is sent to an Intelligent Traffic
Routing and Control (INTRAC) unit resident on a Service Control Point
(SCP) which determines whether the call is to an ISP. If the call is to
an ISP, the INTRAC unit polls a Remote Authentication Dial-In User
Service (RADIUS) server to determine whether resources are available. The
RADIUS server tracks the resources of the ISP and of other ISPs and
informs the SCP of the available resources. The SCP then inserts the
Local Routing Number (LRN) of the preferred resource into a reply that is
sent to the central office. If resources are not available, the call is
terminated before signaling occurs with any switch associated with the
ISP. On the other hand, when resources are available, the subscriber can
be directed to the preferred resource for the subscriber. The subscriber,
for instance, can be directed to an access server within the ISP that has
excess capacity or can be directed to an access server that provides the
best service for the subscriber, whereby subscribers can be directed to
X2 type service if they have an X2 modem or to K56Flex type service if
they have a K56Flex modem. As another example, if one ISP is at maximum
capacity, the subscriber can be directed to a second back-up ISP.