With a "Left" office FXO port connected to a "Right" office FXS port (purple connection), users of the two FacetPhone systems can call each other through the network.  In addition, the users in the "Left" office can make out-going calls using the trunk lines of the "Right" office. With the "Left" office interconnect FXO port defined as Trunk Group 1, and the "Right" office interconnect FXS port defined as Station 101, users in the "Left" office can become Station 101 of the "Right" office system by dialing:  8 1.  After a "Left" office user dials  8 1  they'll get a dial-tone from the "Right" office system.  Then they can either dial a "Right" office extension or dial  9  and a phone number to call out using "Right" office trunk lines. Users in the "Right" office can call in to the "Left" office FacetPhone system by dialing the interconnect station number:  101.  The "Left" office system will see the call as an outside call coming in on Trunk 1.  As an outside caller coming in they will not be able to dial out trunk lines of the "Left" office.