Phone line is not getting disconnected when I hang the line with DISA enabled in it. I call from Home to a line connected to the Nortel system, I get a sluttered dial tone then I enter a COS pwd and then make a call. After I hang up the phone the line which I dialed to get sluttered tone does not disconnect. Disconnect supervision is enabled to that line, even then the line is not getting disconnected. Can someone please help me in fixing this issue.