We have a 20 year old Interlogix system that our homebuilder installed and have had Xfinity X1 for about 2 years with no problem (Roadrunner and Comcast before that). About 4 weeks ago we started getting a Communications Fault and the call history would show the Interlogix calling out a number of times... if it tried 8 times and failed, then it would show the Comm. Fault. I spoke to our monitoring service (not the same company that did the original install) and they asked if we had Comcast. Their response was that Comcast digitally compresses the VOIP signal and that results in unreliable communication from many alarm systems. They also suggested the wireless solution ($150 for the hardware + $50 installation), and if we dropped our VOIP line the Comcast then the monthly monitoring increase ($9) should be close to a wash. I hate to spend $200 on a 20 y/o system but it sounds like the best solution.
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