Fxo Supplementary Services - AudioCodes Mediant 800B User Manual

User's Manual
26.14.2.3

FXO Supplementary Services

The FXO supplementary services include the following:

Hold / Transfer toward the Tel side: The ini file parameter LineTransferMode must
be set to 0 (default). If the FXO receives a hook-flash from the IP side (using out-of-
band or RFC 2833), the device sends the hook-flash to the Tel side by performing one
of the following:

Performing a hook flash (i.e., on-hook and off-hook)

Sending a hook-flash code (defined by the ini file parameter HookFlashCode)
The PBX may generate a dial tone that is sent to the IP, and the IP side may dial digits
of a new destination.

Blind Transfer to the Tel side: A blind transfer is one in which the transferring phone
connects the caller to a destination line before ringback begins. The ini file parameter
LineTransferMode must be set to 1.
The blind transfer call process is as follows:

FXO receives a REFER request from the IP side

FXO sends a hook-flash to the PBX, dials the digits (that are received in the
Refer-To header), and then drops the line (on-hook). Note that the time between
flash to dial is according to the WaitForDialTime parameter.

PBX performs the transfer internally

Hold / Transfer toward the IP side: The FXO device doesn't initiate hold / transfer as
a response to input from the Tel side. If the FXO receives a REFER request (with or
without replaces), it generates a new INVITE according to the Refer-To header.
26.14.3 Call Termination on FXO Devices
This section describes the device's call termination capabilities for its FXO interfaces:

Calls terminated by a PBX (see 'Call Termination by PBX' on page 409)

Calls terminated before call establishment (see 'Call Termination before Call
Establishment' on page 410)

Ring detection timeout (see 'Ring Detection Timeout' on page 411)
26.14.3.1 Calls Termination by PBX
The FXO device supports various methods for identifying when a call has been terminated
by the PBX.
The PBX doesn't disconnect calls, but instead signals to the device that the call has been
disconnected using one of the following methods:

Detection of polarity reversal/current disconnect: The call is immediately
disconnected after polarity reversal or current disconnect is detected on the Tel side
(assuming the PBX/CO generates this signal). This is the recommended method.
Relevant parameters: EnableReversalPolarity, EnableCurrentDisconnect,
CurrentDisconnectDuration, CurrentDisconnectDefaultThreshold, and
TimeToSampleAnalogLineVoltage.

Detection of Reorder, Busy, Dial, and Special Information Tone (SIT) tones: The
call is immediately disconnected after a Reorder, Busy, Dial, or SIT tone is detected
on the Tel side (assuming the PBX / CO generates this tone). This method requires
the correct tone frequencies and cadence to be defined in the Call Progress Tones
file. If these frequencies are unknown, define them in the CPT file. The tone produced
by the PBX / CO must be recorded and its frequencies analyzed. Adding a reorder
Version 6.6 409
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Mediant 800B GW & E-SBC