Just curious as I installed 7100 with 12 SMT handsets and 2 soft phones, 4 MGI ports with 4 channels of ISDN2e.

Say 2 external calls were in use and another two internal extensions were in use, Using up all 4 MGI ports, if the system was to receive an incoming call via the 3rd isdn channel what would happen? Would the caller receive a network message? Busy tone?

I understand the system has the MPS function, however this isn't currently activated.