Yikes! That's a pretty old unit - if it's not too expensive to switch to CICS (like if you have a bunch laying around) I would say that's the way to go.

Otherwise you could probably do the DR5 software to hotline to a DN, then setup an "Answer DN" button on each phone that needs to ring. I believe that was the method the old Algo/Nortel doorphones used to specify in the manual.

[Linked Image from web.atcomsystems.ca]
Looking for a VoIP Phone Canada provider? Put Atcom's valuable VoIP expertise to work for your business today!