Call Transfer Parameters

'Enable Transfer'

configure voip > gateway dtmf-supp-service supp-service-settings > enable-transfer

[EnableTransfer]

Enables the Call Transfer feature.

■

[0] Disable

■

[1] Enable = (Default)

✔

If the transfer service is enabled, the user can activate Transfer using hook-flash signaling. If this service is enabled, the remote party performs the call transfer.

Note:

■

To use call transfer, the devices at both ends must support this option.

■

To use call transfer, set the parameter EnableHold to 1.

'Transfer Prefix'

configure voip > gateway dtmf-supp-service supp-service-settings > transfer-prefix

[xferPrefix]

Defines the string that is added as a prefix to the transferred/forwarded called number when the REFER/3xx message is received.

Note:

■

The number manipulation rules apply to the user part of the Refer-To and Contact URI before it is sent in the INVITE message.

■

The parameter can be used to apply different manipulation rules to differentiate the transferred/forwarded call number from the originally dialed number.

'Enable Semi-Attended Transfer'

semi-att-transfer

[EnableSemiAttendedTransfer]

Defines what the device does when a transfer is initiated while in Alerting state.

■

[0] Disable = (Default) Sends a SIP REFER message with the Replaces header.

■

[1] Enable = Sends a SIP CANCEL message and after a SIP 487 response is received, sends a REFER without the Replaces header.

'Blind'

configure voip > gateway analog keypad-features > blind-transfer

[KeyBlindTransfer]

Defines the keypad sequence to activate blind transfer for established Tel-to-IP calls. The Tel user can perform blind transfer by dialing the [KeyBlindTransfer] digits, followed by a transferee destination number.

After the KeyBlindTransfer DTMF digits sequence is dialed, the current call is put on hold (using a Re-INVITE message), a dial tone is played to the channel, and then the phone number collection starts.

After the destination phone number is collected, it is sent to the transferee in a SIP REFER request in a Refer-To header. The call is then terminated and a confirmation tone is played to the channel. If the phone number collection fails due to a mismatch, a reorder tone is played to the channel.

Note: For analog interfaces, it is possible to configure whether the KeyBlindTransfer code is added as a prefix to the dialed destination number, by using the parameter KeyBlindTransferAddPrefix.

configure voip > gateway digital settings > blind-xfer-add-prefix

[KeyBlindTransferAddPrefix]

Determines whether the device adds the Blind Transfer code (defined by the KeyBlindTransfer parameter) to the dialed destination number.

■

[0] = Disable (default)

■

[1] = Enable

Note: The parameter is applicable only to analog interfaces.

configure voip > gateway digital settings > blind-xfer-disc-tmo

[BlindTransferDisconnectTimeout]

Defines the duration (in milliseconds) for which the device waits for a disconnection from the Tel side after the Blind Transfer Code (KeyBlindTransfer) has been identified. When this timer expires, a SIP REFER message is sent toward the IP side. If the parameter is set to 0, the REFER message is immediately sent.

The valid value range is 0 to 1,000,000. The default is 0.

'Call Transfer using re-INVITEs'

configure voip > sip-definition settings > enable-call-transfer-using-reinvites

[EnableCallTransferUsingReinvites]

Enables call transfer using re-INVITEs.

■

[0] Disable = (Default) Call transfer is done using REFER messages.

■

[1] Enable = Call transfer is done by sending re-INVITE messages (instead of REFER).

Note:

■

The device uses two DSP channels per transferred call. Therefore, make sure that the device's License Key includes a license for DSP resources ('DSP Channels').