OsmocomBB MNCC socket implementation without LCR

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Harald Welte laforge at gnumonks.org
Fri Mar 17 15:49:50 UTC 2017

hi Gerard,

On Fri, Mar 17, 2017 at 02:47:18AM -0700, Gerard Pinto wrote:
> I have been working with Layer23 stack of OsmocomBB since a couple of
> months.
> I decided to try MNCC socket interface without LCR (I'm aware there is an
> implementation embedded in LCR gsm-ms).

Just a quick note: There's mncc-python at
http://git.osmocom.org/mncc-python/ which you can use to interface from
external programs/scripts, if you'd like.

> Problem: I'm unable to make a call on live network, although it does channel
> allocation, ciphering etc.
> Flow:
> 1. Create MNCC struct and write on to the osmocomBB socket
> 2. OsmocomBB parses it well and request for channel, ciphering mode, init
> MM, sending SETUP etc works great.
> 3. However, in response to step.2 after sending SETUP it returns with (ms 1)
> Received 'RELEASE_COMPL' in CC state INITIATED. Why does it release CC?

It would be best if yo could include GSMTAP protocol traces of such
situations, so one can analyze what happens.

Also, you can compare the traces of working (no mncc?) and non-working
(mncc) cases.

- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
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