Das Asterisk Buch

Versucht bei ausgehenden Telefonaten Anrufbeantworter bei der Gegenstelle zu erkennen (AMD steht für Answering Machine Detection).

AMD([initialSilence[,greeting[,afterGreetingSilence[,totalAnalysisTime[,minWordLength[,betweenWordsSilence[,maxNumberOfWords[,silenceThreshold]]]]]]]])

Wird z. B. über ein CallFile ein ausgehender Anruf initiiert, so kann in der aufgerufenen Extension die Applikation AMD() benutzt werden, um bei der Gegenstelle einen Anrufbeantworter zu erkennen. Default-Parameter können in der Datei amd.conf eingestellt werden.

Diese Applikation setzt als Ergebnis die Channel-Variablen AMDSTATUS und AMDCAUSE.

AMDSTATUS kann die folgenden Werte bekommen:

AMDCAUSE kann die folgenden Werte bekommen:

; Von einem CallFile wird diese Extension aufgerufen:
exten => 10,1,AMD()
exten => 10,n,Goto(Status-${AMDSTATUS})
exten => 10,n(Status-HUMAN),Playback(spam)
exten => 10,n,Hangup()
exten => 10,n(Status-MACHINE),Hangup()
exten => 10,n(Status-NOTSURE),Hangup()
exten => 10,n(Status-HANGUP),Hangup()

Asterisk-Versionen: 

        |     |        | 1.4 |————————| 1.6 |————————

Interner Hilfetext zu dieser Applikation in Asterisk 1.4: 

  -= Info about application 'AMD' =-

[Synopsis]
Attempts to detect answering machines

[Description]
  AMD([initialSilence][|greeting][|afterGreetingSilence][|totalAnalysisTime]
      [|minimumWordLength][|betweenWordsSilence][|maximumNumberOfWords]
      [|silenceThreshold])
  This application attempts to detect answering machines at the beginning
  of outbound calls.  Simply call this application after the call
  has been answered (outbound only, of course).
  When loaded, AMD reads amd.conf and uses the parameters specified as
  default values. Those default values get overwritten when calling AMD
  with parameters.
- 'initialSilence' is the maximum silence duration before the greeting. If
   exceeded then MACHINE.
- 'greeting' is the maximum length of a greeting. If exceeded then MACHINE.
- 'afterGreetingSilence' is the silence after detecting a greeting.
   If exceeded then HUMAN.
- 'totalAnalysisTime' is the maximum time allowed for the algorithm to decide
   on a HUMAN or MACHINE.
- 'minimumWordLength'is the minimum duration of Voice to considered as a word.
- 'betweenWordsSilence' is the minimum duration of silence after a word to
   consider the audio that follows as a new word.
- 'maximumNumberOfWords'is the maximum number of words in the greeting.
   If exceeded then MACHINE.
- 'silenceThreshold' is the silence threshold.
This application sets the following channel variable upon completion:
    AMDSTATUS - This is the status of the answering machine detection.
                Possible values are:
                MACHINE | HUMAN | NOTSURE | HANGUP
    AMDCAUSE - Indicates the cause that led to the conclusion.
               Possible values are:
               TOOLONG-<%%%%d total_time>
               INITIALSILENCE-<%%%%d silenceDuration>-<%%%%d initialSilence>
               HUMAN-<%%%%d silenceDuration>-<%%%%d afterGreetingSilence>
               MAXWORDS-<%%%%d wordsCount>-<%%%%d maximumNumberOfWords>
               LONGGREETING-<%%%%d voiceDuration>-<%%%%d greeting>

Differenz des internen Hilfetexts von Asterisk 1.2 zu 1.4: — in Asterisk 1.2 nicht vorhanden —

Differenz des internen Hilfetexts von Asterisk 1.4 zu 1.6: 

--- in Asterisk 1.4
+++ in Asterisk 1.6
@@ -4,9 +4,9 @@
   Attempts to detect answering machines

   [Description]
-    AMD([initialSilence][|greeting][|afterGreetingSilence][|totalAnalysisTime]
-        [|minimumWordLength][|betweenWordsSilence][|maximumNumberOfWords]
-        [|silenceThreshold])
+    AMD([initialSilence],[greeting],[afterGreetingSilence],[totalAnalysisTime]
+        ,[minimumWordLength],[betweenWordsSilence],[maximumNumberOfWords]
+        ,[silenceThreshold],[|maximumWordLength])
     This application attempts to detect answering machines at the beginning
     of outbound calls.  Simply call this application after the call
     has been answered (outbound only, of course).
@@ -26,7 +26,8 @@
   - 'maximumNumberOfWords'is the maximum number of words in the greeting.
      If exceeded then MACHINE.
   - 'silenceThreshold' is the silence threshold.
-  This application sets the following channel variable upon completion:
+  - 'maximumWordLength' is the maximum duration of a word to accept. If exceeded then MACHINE
+  This application sets the following channel variables upon completion:
       AMDSTATUS - This is the status of the answering machine detection.
                   Possible values are:
                   MACHINE | HUMAN | NOTSURE | HANGUP
@@ -37,3 +38,4 @@
                  HUMAN-<%%%%d silenceDuration>-<%%%%d afterGreetingSilence>
                  MAXWORDS-<%%%%d wordsCount>-<%%%%d maximumNumberOfWords>
                  LONGGREETING-<%%%%d voiceDuration>-<%%%%d greeting>
+                 MAXWORDLENGTH-<%%%%d consecutiveVoiceDuration>

Siehe auch. Abschnitt 2, „Call Files“