Answer Machine Detector (Amd) - AudioCodes Mediant 600 User Manual

SIP User's Manual
9.9

Answer Machine Detector (AMD)

Answering Machine Detection can be useful in automatic dialing applications. In some of
these applications, it is important to detect if a human voice or answering machine is
answering the call. Answering Machine Detection can be activated and de-activated only
after a channel is already open. The direction of the detection (PSTN or IP) can be
configured (using the parameter AMDDetectionDirection - refer to ''Media Server
Parameters'' on page 342), as well as the detector detection sensitivity using the parameter
AMDDetectionSensitivity - refer to ''Configuring the IPmedia Settings'' on page 78).
Upon every Answering Machine Detection activation, the device can send a SIP INFO
message to an Application server, notifying it of one of the following:
Human voice has been detected
Answering machine has been detected
Silence (i.e., no voice detected) has been detected
The table below shows the success rates of the AMD feature for correctly detecting live and
fax calls:
Table 9-5: Approximate AMD Detection Sensitivity (Based on North American English)
AMD Detection
Sensitivity
0 (Best for
Answering
Machine)
1
2
3 (Default)
4
5
6
7 (Best for Live
Calls)
A pre-requisite for enabling the AMD feature is to set the ini file parameter
EnableDSPIPMDetectors to 1. In addition, to enable voice detection, required once the
AMD detects the answering machine, the ini file parameter EnableVoiceDetection must be
set to 1.
Version 5.8
Success Rate for Live Calls
-
82.56%
85.87%
88.57%
88.94%
90.42%
90.66%
94.72%
Performance
Success Rate for Answering Machine
495
9. IP Telephony Capabilities
-
97.10%
96.43%
94.76%
94.31%
91.64%
91.30%
76.14%
September 2009