Answering machine detection works by calculating the numbers of words and amount of silence between them when the call is first answered. This method is not 100% effective but can detect almost all standard answering machine messages.

Notes on answering machine detection: 

It can only be used in ratio/predictive dialing modes.
It will not detect 100% of the answering machines.
Calls will take longer to get to agents, because the system listens to the first few seconds of the call.

Enabling Answering Machine Detection for a Campaign 

1. Login to the Vicidial Admin page.
2. Click the Campaigns tab at the top of the page.
3. Click the Modify link for the campaign you would like to change.
4. Click the Detail View link near the top of the page.
5. Find the "Campaign VDAD exten" setting and set it to 8369.
6. Click the Submit button to save the settings.