In order for the M1 to have Proper Line Seizure It Must be the first device the Incoming phone Line connects (RING & TIP) the House Phones will connect to R1 and T1. Refer to the M1 Installation Manual for more information on connecting the incoming phone line. Basically Your VoIP “box” should have a output to simulate Plain Old Telephone Service (POTs) Voltage and Current. This Output will connect to RING and TIP and the house phones connect to R1 and T1. Are you wanting to have the M1 send alarm signals to a Central Monitoring Service? If so you should contact your Internet Service Provider to make sure they will guarantee the signals will go through. If properly wired the M1 should be able to seize the Line to regain Dial Tone and attempt to connect with your CS Receiver — HOWEVER — if the Internet connection should momentarily drop the connection the M1 will not receive the acknowledgement of the communication and will LOG a Failed To Communicate”. If your Central Station has either the DSC Surgard III or the GE OH2000E Internet Receiver you can send signals through the M1XEP to these Internet Receivers.