One-Stage Dialing
One-stage dialing is when the FXO device receives an IP-to-Tel call, off-hooks the PBX line connected to the telephone, and then immediately dials the destination telephone number. In other words, the IP caller doesn't dial the PSTN number upon hearing a dial tone.
One-stage dialing incorporates the following FXO functionality:
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Waiting for Dial Tone: Enables the device 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. |
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Time to Wait Before Dialing: 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. |
The ini file parameter IsWaitForDialTone must be disabled for this mode.
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Answer Supervision: The Answer Supervision feature enables the FXO device to determine when a call is connected, by using one of the following methods: |
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Polarity Reversal: the device sends a 200 OK in response to an INVITE only when it detects a polarity reversal. |
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Voice Detection: the device sends a 200 OK in response to an INVITE only when it detects the start of speech (fax or modem answer tone) from the Tel side. Note that the IPM detectors must be enabled. |