Points B and C are local, while A is a long distance station. I want to call from A to C. Now A and C are charged long distance. But I have a virtual hotline between A and B, which costs me nothing. At point B, I want such a telephone/pabx system, that can intake two phone lines, and one phone line, I use the A-B hotline for a free call to B, and use the other phone line to connect B to C (which will be a local call) so that effectively, my call from A to C becomes a local call also. So here is how it should go: Sitting at A, I dial B on line 1 at B. Then I dial a predefined extension and the device at B uses line 2 at B to call C, and then let A talk to C using these two lines. Any variation is also acceptable. Do such systems exist. What are they called. Where should I start looking for purchasing one.