Thanks for the VoIP/ATA information. When you mention the caller ID is in quotes - that's how it's displayed on a Caller ID built into a phone or standalone unit?

Even if I didn't have the CO line I'd have the key system. Now that school is out for the year someone is here at times so the intercom is used as a typical intercom again. Also use it to control other circuits for lights. Although I don't use the remote function much now, I'm able to call the answering system via the intercom and access it remotely. There's a lot that can be done with the Melco intercom. I may have one more if it fails, otherwise I may need to convert a couple more line keys for other functions.

The VoIP using an ATA is all new to me, sort of. Had a Magic Jack several years ago connected to line 2 of the key system (formerly a CO line for voice and internet dial-up). It actually wasn't bad at all - at the time I had DSL and several others could be doing things online so the audio could get choppy. With the current cable internet and it's usage that's not a concern. Whatever I get will be used with the 1A2 system. The only ringer load will be an electronic phone. That phone's tone ringer is fed into a paging amplifier.