The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 1988
Filed:
Sep. 05, 1986
Paul D Hunter, Naperville, IL (US);
William W Parker, Naperville, IL (US);
Benjamin C Widrevitz, Downers Grove, IL (US);
American Telephone and Telegraph Company, AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A virtual PBX capability is provided to a group of user packet stations served by a packet switching system. The system establishes a virtual circuit between each distinct pair of stations in the group. The stations exchange signaling packets via the virtual circuits and respond to such packets by coordinating the initiation and disconnection of voice, data, or image calls. All call processing, including the provision of features such as call forwarding and automatic callback, is accomplished by the stations without the aid of the switching system. A fraud prevention mechanism is included in the switching system to prevent unauthorized stations from communicating as part of the virtual PBX group.