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 register 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)