Special T1/E1 Cabling Requirements; T1M Or T1M-2 Modules Used For Private Networking; Two-Port Loop Start Module - Mitel MiVoice Office 250 Installation And Administration Manual

T1 circuits are assigned hardware address numbers according to the module's bay in the chassis
and the location of the circuit on the module. For example, T1 circuit 3.1.21 is the 21st circuit on the
T1M or T1M-2 module installed in Bay 3 of the chassis.

Special T1/E1 Cabling Requirements

Mitel recommends that special high-speed data cable with the following characteristics be used for
all T1/E1 installations:
• 22 AWG (0.64 mm)
• Individually shielded two-pair (or with the transmit and receive pairs run in separate cables or
binder groups)
• ABAM or PIC (a level-3 cable designed specifically for the T-carrier transmission rate)
• Maximum capacitance of 15 pF/ft
• Maximum attenuation of 5 dB/1000 ft (300 m) at 772 kHz and 70 °F (21 °C)
The programming prompts for LBO attenuation (and DSX mode, if used) assume that T1/E1
cabling possessing the above characteristics is being used. When transmitting over shorter
distances, it may be possible to use standard two-pair voice frequency cable instead;
NOTE
however, the programmer may have to compensate by selecting a smaller LBO setting. Also,
no matter which type of cable is used, the transmit and receive pairs must be shielded from
each other or run in separate cables or binder groups.

T1M or T1M-2 Modules used for Private Networking

When using private networking to connect two nodes, each network span requires two T1M or T1M-2
modules, one for each end of the span. If using the Telco to connect the private networking span,
order a clear channel, point-to-point T1 span from the service provider, for each networking span.
Do not order premium PRI service, even though PRI will be used.
The Mitel system requires T1 channel 24 for the D-channel in any network span.
NOTE
When a T1M or T1M-2 module is programmed for networking (Private Network switch type), the
system automatically creates a node trunk group. All B channels residing on the same T1M or T1M-2
module are in the same node trunk group.

Two-Port Loop Start Module

Each two-port Loop Start Module (LSM-2) supports one or two analog loop start/CO trunks in the
United States, and each quad Loop Start Module (LSM-4) supports 1–4 of the same type trunk.
LSMs support the same number of local exchange trunks in Europe.
For optimal CO trunk transmission performance, each analog loop start trunk interface should be
"hybrid balanced" in DB programming. Hybrid balancing refers to selecting the balance network that
best matches the trunk's impedance. To determine an appropriate hybrid balance setting for analog
loop start trunk interfaces, refer to the MiVoice Office 250 Features and Programming Guide.
LSM circuits incorporate a self-resetting fuse that should never need replacement. If the fuse should
open momentarily—perhaps as the result of a lightning strike—it should reset within a few seconds.
Specifications
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