Nortel Networks BCM1000 Benutzerhandbuch

Chapter 12 Installing Analog Terminal Adapters

Installation and Maintenance Guide

The maximum loss for ATA 2 to Central Office (CO) configuration, shown in 

, must not 

exceed 10 dB.

Figure 64   Insertion loss from the CO to the analog telephone

Measure the total insertion loss between the CO and analog device by using standard dial up test 
lines with a transmission test set. For example, Hewlett-Packard 4935A Transmission Test Set.

Use this procedure to measure the insertion loss from the CO to the analog device:

Establish a connection to the 1 mW, 1 kHz, CO service line with an analog telephone attached 
to the ATA 2.

Ensure that the analog port terminates correctly in 600 ohms:

Replace the analog telephone with the test set

Use 

RECEIVE/600 OHM/HOLD

 mode on the test set

Ensure that the test set connects in parallel to the service line before removing the analog 
telephone or the line drops.

Remove the single-line telephone.

Measure the 1 kHz tone at the far end of the analog port, which is where the analog loop ends 
and where the analog device connects.)

Longitudinal balance to ground

50 dB 
60 to 4,000 Hz 
With IEEE 455-1976 test

Overload level

3 dB

The tone must be greater than - 10 dB (for example: - 9 dB is acceptable).

Analog telephone

ATA 2

BCM1000

Business Communications Manager to ATA 2

ATA 2 to Business Communications Manager

10 dB Max

Cable loss

Central Office 
cable loss