Patent ID: 8509222

Claim:
A method for routing a call from a customer to a destination, the method comprising: at an application server: intercepting a call setup message sent from a customer switch to a switch intended to signal the switch to perform a call routing function or request a call routing function be performed, the call routing function determines a route for the switch to use to carry the call to the destination, the route so determined is a switch-determined route; intercepting a call release message sent from the switch to the customer switch intended to signal the customer switch of network congestion associated with the switch-determined route; in response to either the call setup message or the call release message being intercepted, querying a routing engine with the destination of the call for a specific route over which to carry the call to the destination, the specific route is queried from a set of routes that is different from another set of routes from which the call routing function determines the switch-determined route; modifying the call setup message to include the specific route, the call setup message so modified is a modified call setup message; responding to the call release message with a re-route call message that includes the specific route; directing the switch with either the modified call setup message or re-route call message to use the specific route to carry the call from the customer to the destination; wherein the application server performs the method without needing a service transfer point 1) to intercept the call setup message and the call release message and 2) to direct the switch with either the modified call setup message or re-route call message.