Most alarm systems use your phone line to send an alarm signal to a monitoring central station. The alarm system control “seizes” the phone line and then dials a phone number that is connected to the alarm monitoring company’s central monitoring receiver equipment. If you are using the phone when the alarm system “seizes” the line, you will be disconnected from your call and all the phones will go “dead” for the period of time that the alarm system control is signaling to the monitoring station (usually the call takes 18-30 seconds).
If your phone line is cut, disconnected or otherwise out of service, the alarm control cannot send a signal to the alarm monitoring center. The local siren will activate if a break-in occurs. Some of the more sophisticated alarm control panels can indicate on the keypad that the phone line is disconnected and can be programmed to trip the alarm siren when the phone line is disconnected and the alarm system is “armed”.
Equipment is available to “back-up” the telephone line with cell phone, radio and internet monitoring. Many customers are using radio, cell or internet for monitoring and bypassing standard phone lines altogether. The exact model and method will depend on the manufacturer you use and the alternative service providers in your area. None of the equipment and corresponding monthly service fee for connecting to the alternative networks are inexpensive. Although the frequency of the phone lines being compromised is possible you need to decide if that risk merits the expense of utilizing these services. In any event, if this is a concern there are solutions available.
VOIP – (Voice over Internet Protocol). Many customers are switching their phone service to VOIP. This is offered by both the cable company and DSL internet providers. While most alarm panels can utilize the VOIP lines for communications, it does present some additional obstacles that are not present with traditional “hardwire” telephone lines. If you have VOIP we would look carefully at how your providers network is configured to make sure you are aware of any potential problems.
If you have switched your service from standard "POTS" (plain old telephone service) to VOIP after your alarm system was already installed, you need to be sure to test your alarm system. The change from "POTS" to VOIP can cause the alarm system seizure to be on the wrong side of the system if the VOIP provider has not wired the system correctly. It is not enough to just have your phone working to ensure that the alarm system will be monitored.