Please help to clarify when %Nxxxx settings got reset

Dieter Spaar spaar at
Wed Jan 7 21:19:36 CET 2009

Hello Pavel,

> As far as i can see for most people %Nxxxx commands are absolutely
> necessary to get a loud and clear sound (especially on remote side)
> without echo during voice conversation.
> We now know all the possible values but some people got mixed results
> with these settings because they're somehow got reset to "No echo
> suppression and noise cancellation". Some say they have to re-issue %N
> commands after every incoming call.
> I hope you're the one who can say exactly when it's best to issue
> those commands to ensure an acceptable sound quality :)

I am sorry to say that I cannot answer this, simply because
 I don't know it without spending probably quite some time
on trying to find out the details. The problem is that the
actual work is done by the DSP inside the Calypso. Besides
that Openmoko has only a very small part of the GSM source
code, we do not have any information about the details going
on in the DSP.

Just a question: Would it be a problem to re-issue the command
every time before or after after accepting a call ? Isn't it possible
to integrate this command into the application which take care
of accepting the phone calls ? If this is an essential command, there
should be a setting for it, similar to adjusting the volume of the

Best regards,

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