There are four RJ-11 connectors for the PBX and four RJ-11 ‘s for the PSTN.
RJ-11 could be used with 2 wires, four wires and even six wires.
There are two trunks per plug. The first trunk uses the normal green and red conductors, the one located on the center of the plug.
The second trunk uses the yellow and black wires, or pair number two on the same plug.
In order to use all eight ports, you need to use a two pair (four conductors) cord from the Quintum to a RJ-11 block (otherwise called biscuit block).
Connect trunk number one to green-red pair, and trunk number two to black-yellow pair.