A device for enabling call forwarding instructions to be given from any
telephone need be connected only to the phone line for which call
forwarding service has been procured and does not require another phone
line to communicate with the device. The device stores the call forwarding
instructions in a recorder. The device detects the short ring that occurs
on the procured service phone line when a call is forwarded and detects
the long ring that occurs when call forwarding is not in effect. Upon
detection of a short ring, the device seizes the procured service phone
line and places a phone call to the phone line to which the previous call
was forwarded. In an alternate embodiment, the device places the phone
call to its own procured service phone line. In both embodiments, the
device is reset to its stand-by state upon detection of a busy signal.
Where a busy signal is not detected, the device transmits a signal that
cancels call forwarding and triggers a timer. If another phone call is
received at the device within the timing cycle of the timer and an
authorization code is received, the device enables the call forwarding
instructions in the recorder to be changed. If those conditions are not
met the instructions in the recorder remain unchanged. Thereafter, the
device twice transmits the stored call forwarding instructions to the
central station and thereby reestablishes call forwarding.