AudioCodes Mediant 500 E-SBC User Manual page 824

Parameter
User's Manual
T1 RAW CAS [3], T1
CAS [2], E1 CAS [8],
E1 RAW CAS [9]
T1 DMS-100 Meridian
ISDN [35]
The valid values of this parameter are described below:

[0] = Not supported (default).

[1] = Supports CAS NFA DMS-100 transfer. When a SIP
REFER message is received, the device performs a Blind
Transfer by executing a CAS Wink, waits for an acknowledged
Wink from the remote side, dials the Refer-to number to the
switch, and then releases the call.
Note: A specific NFA CAS table is required.

[2] = Supports ISDN (PRI/BRI) transfer - Release Link Trunk
(RLT) (DMS-100), Two B Channel Transfer (TBCT) (NI2),
Explicit Call Transfer (ECT) (EURO ISDN), and Path
Replacement (QSIG). When a SIP REFER message is received,
the device performs a transfer by sending Facility messages to
the PBX with the necessary information on the call's legs to be
connected. The different ISDN variants use slightly different
methods (using Facility messages) to perform the transfer.
Notes:

For RLT ISDN transfer, the parameter
SendISDNTransferOnConnect must be set to 1.

The parameter SendISDNTransferOnConnect can be used
to define if the TBCT/ECT transfer is performed after receipt
of Alerting or Connect messages. For RLT, the transfer is
always done after receipt of Connect
(SendISDNTransferOnConnect is set to 1).

This transfer can be performed between B-channels from
different trunks or Trunk Groups, by using the parameter
EnableTransferAcrossTrunkGroups.

The device initiates the ECT process after receiving a SIP
REFER message only for trunks that are configured to User
side.

[3] = Supports CAS Normal transfer. When a SIP REFER
message is received, the device performs a Blind Transfer by
executing a CAS Wink, dialing the Refer-to number to the
switch, and then releasing the call.

[4] = Supports QSIG Single Step transfer (PRI):
IP-to-Tel: When a SIP REFER message is received, the device
performs a transfer by sending a Facility message to the PBX,
initiating Single Step transfer. Once a success return result is
received, the transfer is completed.
Tel-to-IP: When a Facility message initiating Single Step transfer
is received from the PBX, a SIP REFER message is sent to the
IP side.

[5] = IP-to-Tel Blind Transfer mode supported for ISDN (PRI)
protocols and implemented according to AT&T Toll Free
Transfer Connect Service (TR 50075) "Courtesy Transfer-
Human-No Data". When the device receives a SIP REFER
message, it performs a blind transfer by first dialing the DTMF
digits (transfer prefix) defined by the parameter XferPrefixIP2Tel
824
Mediant 500 E-SBC
Description
[1] CAS NFA DMS-100 or [3] CAS
Normal transfer
RTL [2] or InBand [5]
Document #: LTRT-10427