VDAAERL(1)						    Voicetronix Telephony Tools 						VDAAERL(1)

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).

VPB driver package						   Oct 11, 2007 							VDAAERL(1)