AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual page 233

Data Communications Support
A DS1 trunk connects to the jack on a 100D module in the control unit.
Even though there is only one physical jack, the 100D module supports
up to 24 logical endpoints or ports for voice and data calls. Each DS0
channel in the DS1 signal corresponds to a trunk or logical ID.
A DS1 trunk provides either T1 or PRI access.
PRI service provides the following benefits:
T1 is the factory setting.
A T1 facility is used for communication with outside analog data
stations. The 24 channels on a T1 facility can be programmed
individually in any combination to emulate a loop-start, ground-
start, E&M tie, or DID trunk, so a single 100D module can replace
24 outside trunks. Digital data calls cannot be placed through this
trunk.
is the standard format provided by connection to a 5ESS
PRI
central office (CO) switch or a 4ESS toll switch. (PRI must be
used for digital data calls).
The 100D module supports any combination of the following AT&T
Switched Network services:
— Accunet switched digital service for 56-kbps and 64-kbps
restricted and 64-kbps clear circuit-switched data calls
— Megacom 800 for incoming domestic toll-free voice calls
Megacom WATS service for outgoing domestic long-
distance voice calls
— Software Defined Network (SDN) for circuit-switched voice
and data calls at up to 56 kbps
Speed. Data calls to outside destinations can be made on the
same B-channels used for voice calls if the service allows.
Modems and dedicated, conditioned trunks are not required.
lNFO-2 automatic number identification (AN I) service. Customers
who subscribe to this service can identify the caller on an
incoming call on a PRI trunk by either telephone number or billing
number.
NOTE
If your system has automatic number identification (AN I), the
display shows the number for the outside caller. Availability of
the caller identification information may be limited by local-
serving (caller's) jurisdiction, availability, or
CO
equipment.
5-15
Outside Trunks