ISDN basic rate interface central office station terminal emulator for customer premises equipment

DETAILED DESCRIPTION The problems and limitations associated with obtaining full channel service over the ISDN BRI interface are overcome by emulating at least one CO station terminal which provides access to a voice channel over a single DSL for user station terminals whether or not they are ISDN BRI compatible.
To this end, an interface is provided for the DSL that emulates an ISDN BRI CO station terminal and acts like a facility to user station terminals.
More specifically, a plurality of CO station terminals are emulated on a single multi-point passive bus terminating the single DSL.
During initialization, each of the emulated CO station terminals sends an identity to the CO switching office which presents the appearance that the software emulated CO station terminal is a physical CO station terminal.
The emulated CO station terminals are configured such that CO features are accessible.
Information from the emulated CO station terminals is mapped into existing system structures where such structures are available and compatible with the information from the emulated terminal.
New structures have been created so that CO supplementary services can be invoked by the emulated CO station terminals.
A technical advantage of the invention is that by employing the emulated ISDN-BRI CO station terminals, non-ISDN BRI user station terminals can make use of advanced ISDN facilities.
Another technical advantage is that one or more user station terminals can access the advanced ISDN facilities via any available DSL.