AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual page 148

Lines and Trunks
Expand the Inspect feature to show DID channels as well as
LS/GS/TIE/Unassigned
A new Inspect screen for DID channels
Programming a DID B-channel automatically adds it to the first DID trunk block.
The following considerations apply:
The maximum number of DID trunks in a DID trunk block is the system
maximum number of trunks (24 or 80, depending on system
configuration).
Only trunks on the 800 DID circuit module and B-channels programmed
as DID on the DS1 facility are allowed in DID trunk blocks.
A DID trunk cannot appear in more than one DID trunk block.
If the administrator wants to move a DID trunk from one block to another,
the trunk simply can be assigned to the new trunk block. The trunk is
automatically removed from the previous trunk block and assigned to the
new trunk block. The trunk then takes on the programmed attributes of
the new trunk block.
A DID trunk always appears in one of the two DID trunk blocks, even if a
physical channel is not present between the circuit module and the CO.
The following options need to be programmed via system programming:
DID Trunk Dialing Protocol Type describes the dialing protocol used
for determining when address digits are sent from the CO to the Release
1.0 system.
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—
DID Trunk Address Signaling Type describes the method by which
address signals are transmitted from the serving CO to the Release 1.0
system.
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—
Expected Number of Digits (a number from 1 to 4, factory setting = 3)
indicates the number of address digits expected from the CO on DID
calls in this trunk block. Assignment of a value greater than 4 or less than
1 will be blocked.
3-14 Direct Inward Dialing (DID) Lines/Trunks
Wink Start (factory setting)—the Release 1.0 system signals the
CO when it is ready to receive incoming address digits.
Immediate Start—the CO sends digits about 65 ms after line
seizure. (This is a criterion required of the serving CO.)
Programming of the Immediate Start type for a trunk block that
uses dual-tone multifrequency (DTMF) for passing address signs
is not allowed.
Dial Pulse (factory setting)
DTMF (not allowed for Immediate Start dialing protocol trunks)