System for connecting public network subscriber and private network subscriber
Patent 5455855 Issued on October 3, 1995. Estimated Expiration Date: 
February 14, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 14, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesPBX equipment with dial signal modification Automatic route selection of a private telephone network path on the basis of a public telephone network number Exchange system for incoming calls from direct-in lines Private network with means for establishing virtual tie trunks between PBXS through ISDN public network Direct dialing-in method in a pabx Virtual private network connecting system Patent #: 5339356 InventorAssigneeApplicationNo. 195083 filed on 02/14/1994US Classes:379/229, Interexchange signalling379/196, At switching center379/198, PBX379/220.01, With interexchange network routing379/225Multi-PBX interconnectionExaminersPrimary: Dwyer, James L.Assistant: Dharia, Parag Attorney, Agent or FirmForeign Patent References
International ClassH04M 003/54Foreign Application Priority Data1993-02-12 JPAbstractA connection system of a public network subscriber and a private network subscriber in ISDN includes a first PBX for connecting the public network subscriber and the public network, a second PBX for the private network subscriber and the private network, and third PBXs for connecting the public line and the private line. The first PBX selects one of the third PBXs as an access point to the private network, and forms a first set-up message having the public line number of the selected access point as a destination, the received private line number as a sub-address, and the public line number of the public network subscriber as a calling party identification. The second PBX selects one of the third PBXs as an access point to the public network, and forms a second set-up message having the private line number of the selected access point as a destination, the received public line number as a sub-address, and the private line number of the private network subscriber as a calling party number. Each of the third PBXs previously stores the identification numbers permitted access to the private network and the public network. Only when the calling party number of the received set-up message is identical to one of the identification numbers, the connection is permitted between the public line and the private line. | |
