Mitel MIVOICE OFFICE 250, Руководство по установке и администрированию

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MiVoice Office 250 Installation and Administration Guide
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Base Server Expansion Modules
This section describes the modules that can be installed in any of the four bays in the HX Controller
chassis or any of the three bays in the CS Controller chassis to expand the capability of the MiVoice
Office 250. Expansion modules include:
• T1/E1/PRI Module, 1-port – T1, T1/PRI, E1/PRI
(PRI requires additional licensing)
• Dual T1/E1/PRI Module, 2-port – T1, T1/PRI, E1/PRI.
(PRI and second port require additional licensing)
• Loop Start Module, 2-port – LSM-2 (no longer in production)
• Loop Start Module, 4-port – LSM-4.
• Basic Rate Module–2, 2-port – BRM-2.
• Digital Desktop Module, 16-port – DDM-16 (HX Controller chassis only)
• Single Line Module, 4-port – SLM-4.
Single and Dual T1/E1/PRI Modules
The T1M and T1M-2 modules support T1, T1/PRI, and E1/PRI spans. T1 refers to a digital method
of transmitting voice and data. It is the 24-channel, time-division multiplex (TDM), 1.544 Mbps pulse
code modulation (PCM) method used in the United States [Europe 2.048 Mbps].
The T1 standard, which was developed as a method of reducing cabling and increasing transmission
quality between distant COs, is a subset of a multi-level Digital Signal (DS) scheme. T1 refers to
the DS1 rate as transmitted across any type of media, such as copper wire, optical fiber, or
microwave.
Since each T1 span actually consists of 24 individual circuits (or channels) multiplexed together, it
is often less expensive to purchase a single T1 span than it is to purchase multiple individual trunks.
Each of the 24 T1 channels can be programmed as a Loop Start, Ground Start, DID, E&M, or OPX
(or as unequipped). Any combination is possible.
“Fractional” T1, often called FT1, is a special T1 service where only a portion of the 24 channels
are used and paid for. To implement FT1 equip only those circuits that are provided.
To interface with the public network, each T1M and T1M-2 module is equipped with an on-board
Channel Service Unit (CSU). Since the CSU is on-board, the programmer must select the line
build-out (LBO) attenuation, which is available from the T1 provider.
To use an external CSU instead, the module can be set to DSX mode. However, the module and
the external CSU must be located in the same building, and the cabling between them must be no
longer than 133 ft.
When a T1 span connects the system to the public network or to another telephone system, the two
phones must communicate at the same frequency. Since it is practically impossible for both phones
to have clocks running at identical frequencies, one phone is given master clock status and the other
phone is given slave clock status. The slave clock can then extract and lock-on to the master clock
frequency from the incoming T1 data. This master–slave synchronization is programmed in the