Method of establishing communication link to one of multiple devices

Abstract

A method of establishing a telephone communication link from a calling line to one of plural peripheral devices associated with a single telephone number in a central office telephone switching system or PBX is comprised of storing in a memory a first table of directory numbers and equipment identifiers associated with each directory number, storing in a memory a second table of references to physical peripheral devices associated with each equipment identifier, receiving a request for service to a particular directory number, accessing the first table using the particular directory number and obtaining references to all equipment identifiers associated therewith, accessing the second table using the particular equipment identifiers associated with the particular directory number and identifying the particular physical peripheral devices associated with the particular identifiers, ringing all of the particular physical peripheral devices, detecting one of the particular physical devices going off-hook, ceasing ringing of all the particular peripheral devices, and establishing a communication link only to the one physical device. One of the devices can be a wired telephone set, and another a cellular phone, which can be associated with a different switching office than the wired telephone set.