Call Flow Description - 3Com VCX V7122 User Manual

Some messages have been omitted from the above drawing for the sake of clarity.

Call Flow Description

Figure 86 on the previous page depicts an example of a standard PSTN IP call (billing-
model: debit).
An incoming PSTN call with a published access number reaches the VCX V7122.
The VCX V7122 accepts the call (sends an Alert message).
The VCX V7122 searches its internal Tel IP Destination Number Manipulation table for
the specific prefix. When it is detected, if the 'Prefix to Add' column corresponds to the
predefined VXMLID parameter (in the example below: http), the VCX V7122 determines
that the incoming call is an IVR call.
Figure 87
Basic ini File VXML Parameters
VXMLID = http
NumberMapTel2IP = 5394288,7,http://10.8.1.19/RadAAA01.txt
The VCX V7122 loads the VoiceXML file (RadAAA01.txt) from an outbound HTTP Server
(10.8.1.19) and stores it in its volatile memory. In
VoiceXML already resides in the VCX V7122.
The VCX V7122 sends an Answer/Connect message.
The following steps are according to the supplied VXML script.
The VCX V7122 starts by playing an initial voice message. This message is composed of
an opening greeting and an interactive menu asking the caller to choose one of the
following options: 1 to make a call, 2 for help, 3 for operator service, 4 to exit.
After pressing the digit 1, the caller is immediately prompted to enter his account number
(usually the card number) and his password or PIN (personal identification number). The
VCX V7122 collects the input DTMF digits and sends an Authentication message to an
outbound RADIUS server.
Only after the call is authenticated successfully (in this stage the RADIUS server returns
the billing-model, in the above example: debit), the caller is asked to enter the number he
wishes to reach, the final destination number. The gateway collects the input DTMF
digits and sends an Authorization message to the RADIUS server.
The RADIUS server determines if the caller is authorized to proceed with the call and
specifies the maximum duration of the call; the VCX V7122 conveys the call to the IP
network and starts an internal timer.
One minute before credit is exhausted (see the VXML parameter
254); the finalalertaudio
endaudio Voice Prompt is played.
240
is played; finally, a minute later, the call is disconnected and the
3Com VCX V7122 SIP VoIP Gateway User Manual
Figure 86 it is assumed that the
finalalerttime on page