Provided by: vpb-utils_4.2.59-2_amd64 
NAME
vdaaerl - Measure the echo-return loss on Voicetronix FXO telephony modules
SYNOPSIS
vdaaerl [options]
DESCRIPTION
The vdaaerl utility tests the echo-return from a telephone line connected to a Voicetronix FXO module,
such as those used on the OpenPCI range of cards. It can scan all available impedance values to find the
best match for a particular line.
It will wait for an incoming call on the port under test. The calling handset should have the microphone
well muted for the duration of the test.
A series of tones will be played down the line to determine the ERL in several parts of the audio
spectrum. You should avoid creating any other noise on the line while this test is running, or the
results may be skewed.
If no --impedance is specified, and the --scan option is not used, then the default impedance value
(based on the port's country selection) will be used.
OPTIONS
The following options are available:
--help, -?
Show summary of options.
--card number
Explicitly select the card to test. Default is card 0.
--port number
Explicitly select the port to test. Default is port 0 of the card being tested.
--impedance number
Test a particular impedance setting [0 - 15].
--scan Test all available impedances.
--playgain db
Set the hardware play gain. Values may range from -12.0 to 12.0.
--recgain db
Set the hardware record gain. Values may range from -12.0 to 12.0.
SEE ALSO
proslicerl(1)
AUTHOR
Ron Lee, Peter Wintulich, David Rowe, Voicetronix <support@voicetronix.com.au> This manual page was written by Ron <ron@debian.org>, for the Debian project (but may be used by others).