ADTRAN AOS Version R10.1.0 Command Reference Manual page 1753

Command Reference Guide
Common low ERL values are between 5 and 8 dB. Acceptable ERL values begin around 12 dB. The
higher the ERL value, the more gain adjustment can be made without introducing echo. The commonly
recommended configuration is a receive gain of 0 dB and a ttransmit gain of +6 dB.
The following is an error that could result by attempting to measure ERL when a measurement sequence is
already active:
% could not run erl test
During test execution, a warning is issued when a test sequence terminates abnormally. Reasons for early
termination include:
• Was not able to seize the line
• Line disconnected during test
• DSP timeout (i.e., when the DSP hardware version does not support this feature)
• Test runs for more than 20 seconds per impedance value (for example, 80 seconds with a 4 impedance
setting)
Usage Examples
The following example tests the FXO interface 0/1 to automatically find the best measured impedance
settings:
(config)#interface fxo 0/1
(config-fxo 0/1)#test erl all auto-set
The following example displays the ERL test status (the output is shown after the command):
(config)#interface fxo 0/1
(config-fxo 0/1)#test erl display-results
Port Impedance
--------------------------------------------------------------------------------------------------------
fxo 0/1 600 c
fxo 0/1 900 r
fxo 0/1 900 c
fxo 0/1 z1
fxo 0/1 z2
fxo 0/1 z3
fxo 0/1 z4
fxo 0/1 z5
60000CRG0-35E
Status Measured ERL
10 dB
8 dB
9 dB
13 dB
11 dB
14 dB
12 dB
test calling
Copyright © 2012 ADTRAN, Inc.
FXO Interface Command Set
1753