17.76. TR6T -Tones are supplied as in a 1TR6 CO 
Feature:
Tones are regulated as in a 1TR6 CO
Tie trunk circuit traffic to a system with no tones
Trunk dial tone on the USER side in the case of a DSS1 system connection
Function:
Parameter TR6T controls the supply of a tone to the calling partner, depending on
trunk
seizure in outgoing and incoming terminating and transit traffic.
Outgoing trunk traffic: When an end-of-dialing message is received from the line,
the tone belonging to this message is activated on the partner device if outgoing
seizure
has taken place by means of a digital tie trunk circuit, interface circuit or CO trunk
circuit in whose COT the TR6T parameter is set.
IMPORTANT:
The function only works if the TNDV parameter is not set in the COT of
the outgoing seized trunk!
Incoming trunk traffic: If the original system sends a setup message without digits,
the system reacts in Voice and 3.1-kHz audio connections by activating a dial tone
if the
parameter TR6T is set on the incoming seized trunk. This is signaled in the Setup
Ack
message in the progress indicator for the device handler.
Transit traffic: When the TR6T parameter is set on the outgoing side or the transit
connection, the incoming alert or disconnect message from the destination system is
checked
on the basis of the progress indicator to see whether a free or busy tone is already
generated in the destination system.
If not, then a separate free or busy tone is supplied by the incoming seized transit
trunk
in the direction of the original system.
IMPORTANT:
The TR6T parameter should be set on the outgoing seized transit trunk
if the external node does not activate a free or busy tone on an incoming call, but
only
sends an Alert or Disconnect signal. The OpenScape 4000 node activates the free or
busy
tone. Disadvantage: Switching delays!
AMO Interrelationships:
COT Classes of Trunks:
TNDV - Tone in end-of-dialing signals activates the partner device of the trunk
Device types:
Digital tie trunk circuits, interface circuits and CO trunk circuits
Network protocols:
CORNV33 - CorNet protocol
CORNV33R - CorNet protocol
ECMA1 - ECMA QSIG V1 protocol
ECMA1R - ECMA QSIG V1 protocol
ECMAV2 - CorNet-NQ Issue 2.1 Dec. 96 Basic ETSI
ECMAV2R - QSIG ETSI ETS 300 172 3rd. with SS 2nd.
PSS1V2 - CorNet-NQ Issue 2.1 Dec. 96 Basic ISO/IEC
PSS1V2R - QSIG ISO ISO/IEC 11572 2nd. with SS
EDSGER - EDSS1 protocol for Germany