Mitel Inter-Tel 5000, Installation And Maintenance Manual

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Chapter 4: Specifications
Connections to the Public Network
Inter-Tel
®
5000 Installation Manual – Issue 2.4, May 2008
Page 4-11
Connections to the Public Network
In the United States, CO trunks are terminated on telephone company 66-type connecting
blocks, as required by FCC regulations. Cross-connect cable connects the 66-type blocks to the
CO terminal blocks on the MDF. The trunks are then connected to the Loop Start Modules
(LSM) using cable terminated with 8-pin plugs wired to RJ-14 specifications. An alternate
method is to interconnect the lines through a patch panel. In Europe, Local Exchange Trunks
are terminated on 237A Krone blocks.
DID trunks are terminated on telephone company RJ-type modular jacks (or on 66-type blocks
that are then cross-connected to modular jack assemblies), as required by FCC regulations.
Two-pair, nonreversing, mod-to-mod line cord is used to connect each DID trunk to the
appropriate jack on the corresponding SLA.
T1 spans and Primary Rate Interface (PRI) spans are terminated on RJ-48C modular jacks or
on 66-type connecting blocks that are then cross-connected to modular jack assemblies, as
required by FCC regulations. Four-pair, nonreversing, mod-to-mod line cord is used to connect
each T1 and/or PRI span directly to the T1 jack on the corresponding T1M or T1M-2 module.
Inter-Tel recommends installing gas discharge tubes with silicon avalanche suppressors on all
non-T1/PRI trunks for lightning protection. For T1, T1/PRI, and E1/PRI spans, the Channel
Service unit (CSU) itself provides the lightning protection. Also, in areas with frequent
occurrences of lightning, it is recommended that the cable between the telephone company
termination and the gas discharge tubes be at least 75 ft (22.5 m) in length. If desired, the cable
may be coiled.
Table 4-7. Trunk Characteristics
Characteristic Specification
Loss from CO to endpoint 0dB (@1 kHz, 0 ft)
Loss from CO to single line set 0dB (@1 kHz, 0 ft)
Loss from CO to CO 0dB (@1 kHz, 0 ft)
Ringer equivalence 0.6B REN
Ringing voltage 40 V
RMS
minimum
Ring frequency 17–63 Hz
Loop current 18 mA, minimum
Protection, tip-to-ring 400 V transient