[Asterisk-Users] Snom100 GSM

[Martin Pycko]

Actually asterisk can decode MSGSM frames and Windows can decode our GSM.
That should work fine.

Martin

On 16 May 2003, Steven Critchfield wrote:

> On Fri, 2003-05-16 at 10:13, Gary wrote:
> > On Fri, 16 May 2003 11:05:47 -0400, Wade Weppler wrote:
> >
> > >The latest SNOM 100 firmware seems to help a bit, but GSM is still unusable.
> > >This seems to be a SNOM problem, and not an Asterisk problem, as other GSM
> > >SIP phones work fine (X-lite).
> >
> > Are you sure ??
> >
> > with the x-ten lite, gsm seems choppy, yet g711 is clear as a bell.
> >
> > i'm wondering that maybe is might be a gsm prob ?
>
> For those that either cross between linux and windows, be aware that the
> way GSM is represented is different. A GSM frame is 32.5 bytes. On
> Windows they place 2 32.5 byte frames together shifting the second frame
> down half a byte to make a 65 byte packet containing 2 frames. On unix
> systems, it is standard to just ignore the final 4 bits of the frame,
> and therefore we can transmit in 33 byte packets a frame and we don't
> use any bit shifting. I'm sure this is where most problems with GSM come
> from.
> --
> Steven Critchfield  <critch at basesys.com>
>
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