Patent ID: 6950507

Claim:
An arrangement comprising: a switching network; a digital network; a first PBX including trunks connected to said switching network, lines adapted to operate with telephonic instruments, a first processor for controlling operation of the first PBX, a first memory associated with said first processor, and a digital port coupled to said first processor, through which information contained in said first PBX can be accessed, and through which control signals can be applied to store in said first memory and thereby control manner of operation of said first PBX; a first security processor for coupling the digital port of said first PBX to said digital network, for insuring that only bona fide messages pass through to said digital port from said digital network; a second PBX including trunks connected to said switching network, lines adapted to operate with telephonic instruments, a second processor for controlling operation of said second PBX, a second memory associated with said second processor, and a digital port coupled to said second processor through which information contained in said second PBX can be accessed, and through which control signals can be applied to store in said second memory and thereby control manner of operation of said second PBX; and a second security processor for coupling the digital port of said second PBX to said digital network, for insuring that only bona fide messages pass through to said digital port from said digital network; wherein said first memory contains a calling plan module that specifies telecommunication capabilities of line A of said first PBX, and a directive that specifies a line B in said second PBX that is to be used instead of line A, and said second memory contains a directive that line B is to be treated as if it is line A, and a module associated with line B that contains a facsimile of said calling plan module contained in said first memory.