Interface with existing system

Hi Folks,

I have a small system that I think is called “Keyless”. These are POTS, GE “Pro Series” business phones, model: 2-9451A. They have a normal set of features, like 4 lines, intercom, page, hold, conference, speaker, and so on. These features are implemented in a distributed way with all the terminals communicating out-of-band on the voice line #1.

I want to add Asterisk so I can get several features, like “forward incoming calls to arbitrary number” – read that “cell phone”, record and play back, “desktop computer as phone terminal” and so on.

Would I put Asterisk “upstream” of my existing terminals, meaning make my desktop phones terminals on the Asterisk system and does that interfere with the existing conversation among the desktop units? Or would I make Asterisk look like the desktop phones, meaning just plug the four POTS lines into Asterisk as I do the existing desktop phones.

It is not at all clear to me that Asterisk can “see” any of the intramural activity among my desktop phones, so I’m not sure how to begin this migration because I don’t quite understand how Asterisk can be instructed from the existing desktop phones.

Many, many questions. Is there a migration guide which describes this sort of a migration?

Thanks for the help,


Asterisk is IP based, so it directly “sees” only VoIP phones. All the other phones (analog, ISDN) need to be connected to Asterisk server via a dedicated PCI card or an external VoIP gateway.

I am fairly sure that Asterisk started with circuit switched telephony, not VoIP.

You are correct.