Asterisk: The Future of Telephony, 2nd Edition

Name

AMD() — Answering machine detection

Synopsis

AMD([initialSilence[,greeting[,afterGreetingSilence[,totalAnalysisTime
[,minimumWordLength[,betweenWordsSilence[,maximumNumberOfWords
[,silenceThreshold]]]]]]]])

This application attempts to detect an answering machine, based on the timing patterns. This application is usually used by outbound calls originated from either call files or from the Asterisk manager Interface. This application sets AMDSTATUS variable is set to one of the following, to show what type of call was detected:

MACHINE

The called party is believed to be an answering machine.

HUMAN

The called party is believed to be a human being, and not an answering machine.

NOTSURE

The application was unable to tell whether the called party was a human or an answering machine.

HANGUP

A hangup occurred during the detection.

The AMD() application also sets a channel variable named AMDCAUSE with the cause that lead to the conclusion stated in the AMDSTATUS variable. The AMDCAUSE variable will be set to one of the following values:

TOOLONG-total_time

INITIALSILENCE-silence_duration-initial_silence

HUMAN-silence_duration-after_greeting_silence

MAXWORDS-word_count-maximum_number_of_words

LONGGREETING-voice_duration-greeting

The parameters to this application all help tune it so that it can more effectively tell the difference between a human and an answering machine. If the parameters are not passed to this application, Asterisk will read the default values as configured in amd.conf. The parameters ...