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).