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       measerl  -  Measure  the  echo-return  loss  on  Voicetronix  telephony


       measerl [options]


       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.


       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.

              Use this option for testing station (FXS) ports.

              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.

              Automatically scan the codec balance values.

              Proto handset mode.

       --loop Enable software loopback.

              Enable the host based echo canceller.


       vpbecho(1), ringstat(1)


       Ron    Lee,    Peter     Wintulich,     David     Rowe,     Voicetronix

       This  manual  page  was written by Ron <>, for the Debian
       project (but may be used by others).