AudioCodes Mediant 2000 User Manual page 558

Parameter
SIP User's Manual
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:
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
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 (configured to "*8" for AT&T service), and
then (after 500 msec) the device dials the DTMF of the
number (referred) from the Refer-To header sip:URI
userpart.
If the hostpart of the Refer-To sip:URI contains the device's
IP address, and if the Trunk Group selected according to the
IP to Tel Routing table is the same Trunk Group as the
original call, then the device performs the in-band DTMF
transfer; otherwise, the device sends the INVITE according
to regular transfer rules.
After completing the in-band transfer, the device waits for
the ISDN Disconnect message. If the Disconnect message
is received during the first 5 seconds, the device sends a
SIP NOTIFY with 200 OK message; otherwise, the device
sends a NOTIFY with 4xx message.

[6] = Supports AT&T toll free out-of-band blind transfer for
trunks configured with the 4ESS ISDN protocol. AT&T
courtesy transfer is a supplementary service which enables
a user (e.g., user "A") to transform an established call
between it and user "B" into a new call between users "B"
and "C", whereby user "A" does not have a call established
with user "C" prior to call transfer. The device handles this
feature as follows:

IP-to-Tel (user side): When a SIP REFER message is
received, the device initiates a transfer by sending a
Facility message to the PBX.
558
Description
Document #: LTRT-68814
Mediant 2000