sundance-communications.com/forum Forums General General Telephone & Systems Information Disconnect Supervision

I am going to be putting a small key system (Vodavi) with voice mail behind a Rolm PBX. The PBX is supplying 4 analog extensions that will be going into my CO card. The Auto Attendant on my voice mail will be answering all incoming calls.

The problem I have is disconnect supervision (Sandman calls it: Open Loop Disconnect or Calling Party Control). When the calling party hangs up, the voice mail/auto attendant never releases the analog port on the PBX.


I found a CPC Generator (MIS1I) from Sandman. I was wondering if anybody has used this product or knows of another product that fixes this problem. The MIS1I only supports one line, so I am going to have to get 4 of these devices. I was hoping that there was a product that was a single unit that accepted multiple lines.

Any help would be appreciated!

The Rolm PBX analog ports will not give any disconnect signal at all.

The best you can do is see if there is a setting in the voicemail programming that will detect dial tone after the party has left a message. Also dial tone on a Rolm is not the same as dial tone from the CO (350/440Hz) If there is not a parameter in the voicemail programming for detecting dial tone maybe there is a timeout setting that can be adjusted. Otherwise every message left will probably have 15-20 seconds of dialtone at the end of the message.

DJ