What are some of the causes of disconnect with voice mail systems?
Most issues coming from voice mail systems come from a failure to disconnect when the far end caller (the person leaving the message) hangs up. This can be an issue with any loop start line. To help prevent this issue, the FXS card can be set to lp-fd (loop forward disconnect). This feature will forward a disconnect signal toward the 2 wire side (analog side) of the FXS card. This will only occur if the switch at the other end of the T1 is set to forward the disconnect. This perimeter will vary from switch to switch, but should be at least 650 ms in duration. Some PBX’s and many Key systems will not detect a calling party disconnect, and will only disconnect when the called party disconnects. As you can see, when the called party is a voicemail or IVR system, this can be a problem, as they don’t know when to hang up. The internal voicemail or IVR solution to the issue is to begin an internal disconnect process, usually with a lack of activity or sounds (voice or dtmf Keys) starting a p
