Two-Stage Dialing; Figure 9-2: Call Flow For Two-Stage Dialing - AudioCodes Mediant 1000 User Manual

One -stage dialing incorporates the following FXO functionality:
Waiting for Dial Tone
The Waiting for Dial Tone feature enables the gateway to dial the digits to the Tel side
only after detecting a dial tone from the PBX line. The ini file parameter
IsWaitForDialTone is used to configure this operation.
Time to Wait Before Dialing
The Time to Wait Before Waiting feature defines the time (in msec) between seizing
the FXO line and starting to dial the digits. The ini file parameter WaitForDialTime is
used to configure this operation.
Note:
Answer Supervision
The Answer Supervision feature enables the FXO gateway to determine when a call is
connected, by using one of the following methods:
•
Polarity Reversal: the gateway sends a 200 OK in response to an INVITE only
when it detects a polarity reversal.
•
Voice Detection: the gateway sends a 200 OK in response to an INVITE only
when it detects the start of speech (or ringback tone) from the Tel side. (Note that
the IPM detectors must be enabled).
9.4.1.2

Two-Stage Dialing

Two-stage dialing is when the IP caller is required to dial twice. The caller initially dials to
the FXO gateway, and only after receiving a dial tone from the PBX (via the FXO gateway),
dials the destination telephone number.
SIP User's Manual
The ini file parameter IsWaitForDialTone must be disabled for this mode.

Figure 9-2: Call Flow for Two-Stage Dialing

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Mediant 1000
Document #: LTRT-83301