At Heathen HQ, we pay nearly $30 a month, and have for years, to maintain a plain-old-telephone-service (“POTS”) line just for the alarm system. We use Vonage for our actual telephone, which is infinitely preferable to AT&T’s products.
I finally got fed up with this, and called ADT to see if there was some way to interface the alarm with Vonage. No, they say. No one seems to know why (I can fax with Vonage; seems like the alarm signal would work, but whatever).
What ADT does offer, though, is a quasi-cellular wireless hookup. The device itself is $99. There is no installation fee. It raises my ADT monitoring cost by $15 a month. It’s a no-brainer; they’re coming to install it this afternoon.
Think about this: Cellular alarm monitoring is more cost-effective than land-land. Why? Because AT&T wants to live in your pocket, that’s why. Treat them accordingly.