AudioCodes Mediant 2000 User Manual page 419

SIP User's Manual
Note:
The SIP call flows below show an example of implementing the device's AMD feature. This
scenario example allows a third-party Application server to play a recorded voice message
to an answering machine.
1. Upon detection by the device of the answering machine, the device sends a SIP INFO
message to the Application server:
INFO sip:sipp@172.22.2.9:5060 SIP/2.0
Via: SIP/2.0/UDP 172.22.168.249;branch=z9hG4bKac1566945480
Max-Forwards: 70
From: sut <sip:3000@172.22.168.249:5060>;tag=1c1505895240
To: sipp <sip:sipp@172.22.2.9:5060>;tag=1
Call-ID: 1-29758@172.22.2.9
CSeq: 1 INFO
Contact: <sip:56700@172.22.168.249>
Supported: em,timer,replaces,path,resource-priority
Allow:
REGISTER,OPTIONS,INVITE,ACK,CANCEL,BYE,NOTIFY,PRACK,REFER,INFO,SUB
SCRIBE,UPDATE
User-Agent: Audiocodes-Sip-Gateway-IPmedia 260_UN/v.5.20A.040.004
Content-Type: application/x-detect
Content-Length: 30
Type= AMD
SubType= AUTOMATA
Version 5.8
The device's AMD feature is based on voice detection for North American
English. If you want to implement AMD in a different language or region, you
must provide AudioCodes with a database of recorded voices in the language
on which the device's AMD mechanism can base its voice detector algorithms
for detecting these voices. The data needed for an accurate calibration should
be recorded under the following guidelines:
•
Statistical accuracy: The number of recordings should be large (i.e.,
about 100) and varied. The calls must be made to different people, at
different times. The calls must be made in the specific location in which
the device's AMD mechanism is to operate.
•
Real-life recording: The recordings should simulate real-life answering of
a person picking up the phone without the caller speaking (until the AMD
decision).
•
Normal environment interferences: The environment should almost
simulate real-life scenarios, i.e., not sterile but not too noisy either.
Interferences, for example, could include background noises of other
people talking, spikes, and car noises.
419
9. IP Telephony Capabilities
October 2009