US Patent 7653184 Selective fax transmission denial within a telephone network

Whether a facsimile transmission tone is within a call is detected before routing the call from a switch of a telephone network to a first telephone line. When the facsimile transmission tone is detected, whether an incoming facsimile transmission transmitted by the call is permitted to be routed to the first telephone line is determined based at least partially on restriction information. Routing of the call from the switch to the first telephone line is denied when the incoming facsimile transmission is not permitted to be routed to the first telephone line.