17.78. TRBA - Transfer before answer to first connection 
Feature:
Introduce consultation before dialing in the case of an outgoing S0/S2 first connection
(XBFADIAL feature)
Introduce consultation after dialing 'free or unanalyzed' in the case of an outgoing
S0/S2
first connection (XBFADIAL feature)
Transfer of a consultation connection if the selected target has not yet responded
to an
outgoing S0/S2 first connection on hold
Function:
The function "Transfer a consultation connection in Voice service if the selected
target
has not yet responded to an outgoing S0/S2 first connection on hold" is only dealt
with
locally in the source node. Other nodes in the network have no knowledge of this function.
This function only works in the source node if the TRBA parameter is set in the COT
of the
outgoing seized trunk - by means of which the initial connection is made - and the
transferring subscriber has entered the special class of service SUTVA (subscriber
can
transfer before answering). In addition, the XBFADIAL "Transfer before answering from
dialing status" or XFBACALL "Transfer before answering from calling status" feature
is to be
released. In conjunction with the release of the ATTR feature "Switching by attendant
console before the externally selected subscriber answers", the TRBA parameter must
be set
in the COT of the trunk with effect from system variant EV3.0 onwards.
AMO Interrelationships:
AMO COT <CSN7 ... Identify DIUS2 trunks on CSN7 networks, China>
AMO FEASU <XBFADIAL/XFBACALL>
IMPORTANT:
The XBFADIAL and XFBACALL features may not be activated
simultaneously.
Device types:
Digital CO trunk circuits, interface circuits and tie trunk circuits
IMPORTANT:
NW trunks with CSN-7 protocol, NAL loop signals, special inter-PBX
signals and all analog tie trunk circuit signals on the first connection without call
status
do not support this function. NW trunks with CSN-7 protocol, NAL loop signals, special
inter-PBX signals and all analog tie trunk circuit signals on the consultation connection
in
calling status and without call connection on the S0/S2 first connection do not support
this
function either. Functional Devices (including SIP phones) do not support this
function.
Protocol variants:
For example, CORNV33, ECMAV2 (CorNet-NQ Issue 2.1 Dec.96 Basic ETSI), PSS1V2 (CorNet-NQ
Issue 2.1 Dec.96 Basic ISO/IEC), Euro-ISDN