How can an incoming wired telephone call be an off-hook warning signal? Happens 20X/day!?

Question

This is coming in on a PBX, and is transferred to random extensions. Phone rings and when you answer it you get a rapid beep (off-hook warning). It is coming from a NYS-owned switch on Pearl Street in Albany NY. They can't trace it. It's driving us nuts.

Answer 1

This is a long shot, but is it possible your PBX is actually causing the problem?  Are you sure the off-hook is coming from the calling number, or is it possible it is your own PBX malfunctioning?

For example, could your PBX not be detecting extension hang-ups properly and generating the off-hook response itself?  Then when someone rings an extension with hang-up detection problems, you pick it up only to hear your own off-hook response from the last call hang-up?

Perhaps a long shot, but worth verifying...