Line Build Out

After the T1 Modem Bank is installed, the carrier will determine the correct setting for Line Build Out (LBO). However, certain determinations based on the following information will need to be entered into your computer.

CSU mode Line compensation: Line attenuation can be set to one of the following: -0.0dB, -7.5dB, -15.0dB, and -22.5dB. Your T1 installer will inform you of the correct setting.

DSX-1 Mode Transmit line buildout: For line compensation, your T1 installer will select a cable length between 0 and 655 feet based upon line length.

CSU Specification

 

Table 2

CSU Technical Description

 

 

 

 

 

 

Line Frequency

1.544 Mb/s +/- 200 b/s

 

 

Line Code

AMI or B8ZS

 

 

Critical Circuitry Power Source

Dry Span, CSU powered form local AC power source

 

 

Line Framing

D4 or ESF

 

 

Line Loopback (LLB) Set Inband Code

(00001) repeating binary pattern (per AT&T Pub 54016 and

 

 

 

ANSI T1.403)

 

 

Line Loopback (LLB) Reset Inband Code

(001) repeating binary pattern (per AT&T Pub 54016 and ANSI

 

 

 

T1.403)

 

 

Line Build Out

0.0, -7.5, -15.0, or -22.5 dB of attenuation

 

 

Pulse Density and Consecutive Zeros

In accordance with requirements of AT&T Pub 62411

 

 

Enforcement

 

 

 

T1 Cable Specification

 

 

Transmitting T1 signals requires two 24 AWG stranded unshielded twisted pair Category 5 cables. A 15’ cable meeting these specifications is shipped with the T1 Modem Bank.

4

T1 Modem Bank

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Digi 90031300 manual Line Build Out, CSU Specification, T1 Cable Specification, CSU Technical Description