MEASERL(1)						    Voicetronix Telephony Tools 						MEASERL(1)

NAME

       measerl - Measure the echo-return loss on Voicetronix telephony hardware

SYNOPSIS

       measerl [options]

DESCRIPTION

       The measerl utility tests the echo-return loss on the phone line.  For hardware that supports it, it can scan through bybrid balance regis-
       ter settings to help establish a lower ERL.  Having a lower ERL improves DTMF cutthrough and audio quality.  The software echo cancellation
       needs at least -6dB before it can make a difference.

       FXS (station) ports should perform this test using the --nohook option with the handset already off hook and the microphone muted.

       FXO (trunk) ports will answer to an incoming call.

       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.

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.

       --nohook
	      Use this option for testing station (FXS) ports.

       --offhook
	      Take an FXO port off hook immediately.  Don't wait for an incoming ring.

       --bal1 value

       --bal2 value

       --bal3 value
	      Set codec hybrid balance registers.  Only for hardware which explicitly supports that.

       --ec   Enable the echo canceller.

       --pg gain
	      Set codec play gain.  Values may range from -12.0 to 12.0.

       --rg gain
	      Set codec record gain.  Values may range from -12.0 to 12.0.

       --dial port
	      Dial out another port on the same card.

       --dial port number
	      Dial number from port on the same card.

       --scan file start end step
	      Scan the hybrid balance register settings from start to end in increments of step, recording the results to file.  Only for hardware
	      that explicitly permits setting these registers.	Valid values for the start and end are in the range 0 - 255.

       --autoscan
	      Automatically scan the codec balance values.

       --handset
	      Proto handset mode.

       --loop Enable software loopback.

       --hostecho
	      Enable the host based echo canceller.

SEE ALSO

       vpbecho(1), ringstat(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						    Jan 4, 2007 							MEASERL(1)