I had to change 3 settings in my ADT GE Concord 4 alarm to have to dial out successfully to the ADT monitoring center. All the setting are under programming and you will need to have the installer code to make the changes. In addition you have to have the alarm wired correctly to have line interrupt to work.
1. Changed setting in the alarm from (wait for dial tone) to (dial out after waiting a few seconds)
2. Changed the setting in the alarm under (disable call waiting) to use the fax prefix of *99. So basically you have to call OOMA to have them disable call waiting, you can’t just enter a disable code like Ma Bell. So this setting is useless to me except that it allows me to enter the *99. Originally added a pause and *99 at the beginning of the caller center number but that only worked 50 % of the time.
3. Changed the SIA/CID reporting from CID to SIA- I think that this is was really the fixed it but I haven’t tried it with only this setting.
Of Note: Most alarm systems have a built-in line voltage meter on the phone line. This is why you will receive a message on the alarm when you alarm is disconnected from a phone line. However, the absence of this message DOES NOT MEAN THAT YOU ALARM CAN CALL HOME, only that the alarm is detecting voltage on the phone line.
To truly test that you alarm can call home you either need to do a phone test from the console or call the alarm company and have them put your alarm in test mode and then set off the alarm. Also you need to do a line interrupt test to make sure it can still dial out after the burglar takes the phone off the hook. Easy enough call the alarm company from your ooma phone and then when the alarm dials out it will have to disconnect you first. Many of the people I have spoken to on this forum who claim to have ADT working were sadly disappointed when then did a phone home test to the central monitoring office. They incorrectly thought that if the alarm is not complaining about not having a phone line then the alarm is working. Good luck and I hope that this helps. It certainly took me long enough to figure it out.