I have a location where I have now put in a 2nd BCM50 because sometimes the T series phones just do not ring. It is still happening, even with the new BCM50 installed. I have witnessed this myself. The calling party hears ringing but the phones do not ring. Rebooting the BCM50 seems to make the problem go away. I do not normally measure voltage at the DMARC but in this case I did because I am running out of ideas on what is causing this problem. Two of the lines are correct (-48VDC) and two of them are backwards (+48VDC). Has anybody seen this phones not ringing issue? Does anyone think the incorrect DMARC voltage could cause something like this to happen? I am running out of ideas so any thoughts/comments are welcome.