registration d the trigger of that service implies that the s cscf hands the control of the session to a specific application server in the home network referenced as the service allowance application e the service allowance application in the home network contacts an application peer in the visited network the external service allowance application in the visited network this one provides the list of service available for roaming users belonging to the requesting home operator this means the local service allowance application in the visited network will implement the rules that determine which specific local services are offered to each requesting home operator these services are sent in the form of ifcs different possibilities to request and send the ifcs for local services are shown in the section below entitled u201c protocol embodiments communication between application servers in different networks u201d f at this point the service allowance application in the home network dynamically updates the s cscf with the new ifcs to be used by the roaming user in the visited network different possibilities to update the s cscf with this information are shown in the section below entitled u201c download local services u201d g once the s cscf is updated the.