I have a user using a DKT2010-SD phone. When she is on a line, and another ext is ringing, both her and the party on the line is hearing ringing from the other line. I remember that this is a feature that can be shut off. Just don't remember how.

Pressing redial and the volume down buttons at the same time will turn it off. Redial and volume up at the same time will turn it back on.

Do I have to be on a call to do this? or Idle?

BTW this phone is on a CIX1200 system

I usually have the person just unplug the set and plug it back in.

I agree with mj_wald this is an anomaly and should be doing this, just unplug the phone from the wall and plug back in and test it should be OK again.

Trust the BobRobert!It works!!!

It would have worked if he had the older DK system, but he posted later that he has a CIX 1200.
mj_wald and Carlos#1 have the better answer.

Thanks Everyone