The customer, as the end user, can access the OpenScape 4000 switching system with this feature by using the protocol and the procedures defined by Telcordia Technologies (previously Bellcore) for the NI BRI. Thus end users can initialize ISDN configurations and set up and release system-internal ISDN connections and ISDN users can communicate with existing networks.

Usually US customers use the NI BRI connection in the OpenScape 4000 as a LAN bridge for teleworking and for connecting ISDN equipment that can then be used for communication along with the devices connected (for example, analog telephones, fax devices (see list of supported devices in FDB2-3 for NI BRI, V1.0, Appendix B). Only those NI BRI functions that are needed to support this customer requirement have been implemented.