Voice calls over Virtual Um
axilirator at gmail.com
Tue Nov 27 15:05:39 UTC 2018
sorry for late response.
> I set up a network with Virtual Um and multiple OsmocomBB
> phones. They register, they can send and receive SMS
> and I wanted to try voice calls.
First of all, it should be noted that voice support in OsmocomBB
is experimental and undocumented. I have been working on GAPK
back-end integration, and it seems you've already found some
branch, but I would recommend to use 'fixeria/audio' instead of
> calls can be established, but GAPK is never initialized and
> again, I never see voice data appearing as an MNCC message.
Please check out the configuration examples  for mobile app.
There you should find the new 'audio' section, where:
means that audio I/O (by default) should be handled by the
hardware (i.e. by Calypso phone). GAPK is not enabled by default.
In order to use GAPK based back-end, use 'gapk':
It probably makes sense to rename 'gapk' to 'alsa', because
at the moment 'gapk' enables both voice playback and capture
using the audio system of the host that running mobile.
> I never seem to receive a GSM_TCHF_FRAME-message on
> the MNCC socket.
This can also be configured:
In this case GAPK is not used, and all TCH frames are being
forwarded to the MNCC handler 'as-is'.
See  commit description for details.
Please also note that audio I/O target != MNCC handler, that
actually implements the Call Control logic. See  for details.
With best regards,
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