Patent ID: 7672438

Claim:
A method for providing multiple line functionality comprising: receiving from a calling party a request to establish a connection with a local telephone installation, wherein: the local telephone installation comprises a first local telephone equipment associated with a first local node, a second local telephone equipment associated with a second local node, and local telephone wiring connected to said first and second local nodes, the local telephone installation being associated for purposes of the public switched telephone network (PSTN) with a single telephone line; and the request is received at a third local node; determining whether the calling party desires to establish a connection to (1) a first telephone extension associated with the first local node or (2) a second telephone extension associated with the second local node; and using a frequency shift that is (1) associated with the desired extension and is (2) not associated with the other extension to establish a connection from the third local node to the desired extension over the local telephone wiring in a manner that does not affect the other extension.