1. A system for mediating an IMS network having a serving call state control function (S-CSCF) for providing session control for user endpoint (UE) devices with an alternative network to create a hybrid network, said system comprising: logic to define a service and corresponding service request code to utilize at least a subset of capabilities provided by said alternative network; logic to provision the S-CSCF to identify and receive an alternative network service request message from a UE, said logic to provision including logic to provide a call model having at least one filter code to associate said alternative network service code with at least one application server (AS) dedicated to serving alternative network service requests, said AS being responsive to service point triggers (SPTs); wherein said AS being in communication with and capable of controlling delivery of at least a subset of services provided by said alternative network.