Patent ID: 7006612

Claim:
A method comprising: storing, as data in a database of a service control point (SCP), one or more calling party identifiers from which facsimile transmission calls are authorized to be completed to a telephone line of a subscriber; detecting, by a service switching point (SSP), a call placed by a calling party and intended for the telephone line of the subscriber; triggering an advanced intelligent network (AIN) trigger based on the call; sending a query message from the SSP to the SCP based on the AIN trigger; accessing, by the SCP, the data from the database in response to the query message to determine if incoming calls from the calling party are authorized; if the calling party is authorized based on the data, sending a response message to the SSP to instruct the SSP to complete the call to the telephone line of the subscriber; and if the calling party is unauthorized based on the data: sensing for a presence of a CNG tone generated by the calling party within the call before the call has been routed to the telephone line of the subscriber; if the CNG tone is present in the call, denying completion of the call to the telephone line of the subscriber; and if the call is absent the CNG tone, sending a response message to the SSP to instruct the SSP to complete the call to the telephone line of the subscriber.