Abstract: Customers that have groups of stations served from multiple digital switching systems, which frequently include mixtures of PBXs and Centrex, require capabilities that will allow those station groups to operate as one global group. This invention permits customer station groups, including PBXs and Centrexes interconnected by private facilities or by the public switched telephone network (including long distance carriers), to act as a single entity that supports integrated voice and data communications. Advantageously, Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI) facilities are used to carry the communications and signaling to and from the PBXs.

Abstract: This invention is generally directed to minimizing the disruption of subscriber selectable features during the transfer of subscriber lines from a first line unit equipment to a second line unit equipment associated with a telecommunications switch. A second data assignment table which is based on a first data assignment table is utilized in conjunction with a digital telecommunications switch to facilitate an improved service transition when subscriber lines are to be transferred from a first type of line unit equipment to a second type of line unit equipment. The data assignment tables contain for each telephone number an identification of a line unit address utilized to support that telephone number and corresponding parameters which identify which customer selectable features are active.

Abstract: A call waiting deluxe method where a switching system forwards calls to a service node that provides specialized call processing, e.g., processing requiring text-to-speech, to a number of switching systems without requiring modification of the hardware design of those systems. Only calls to busy called stations are forwarded to the service node using a call forwarding-busy line feature to avoid unnecessary delays and excessive service node traffic for normal calls. The service node uses the same directory number that was initially dialed for the call, in invoking a call waiting-originating feature which takes precedence over the call forwarding-busy line feature and results in the transmission of a call waiting signal to the called station. The service node obtains the calling party name from a database and responds to a flash signal from the called station by speaking the calling party name to the called party.