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Harald Welte laforge at gnumonks.orgHi Andreas,
On Sun, Jun 14, 2009 at 11:23:54PM +0200, Andreas.Eversberg wrote:
> > If anyone wants to look further into this, I'm happy to record some
> > PCAP files with some example RTP/RTCP dumps. If you want, even combined
> > with the TCP connection to the BSC, so you have a correct timeline and
> > know what the BSC told the BTS when, and how the BTS reacted to that.
>
> i would like to see some of this payload, but without any BSC traffic.
> when i see in the future, i see that a bts directly forwards rtp data to
> remote sip phone or media gateway or other bts. therefore it must be a
> standard. i think it is gsm audio coded.
After I have digged a bit further, it seems like the FR and EFR RTP payload
is conformant with section 4.5.8 and 4.5.9 of RFC3551. Therefore, no mystery
is expected here.
I'm currently too busy (travelling in about 6 hours and still have way
too much work to consider any sleep tonight) to do some RTP captures, but
at least RFC3551 should give you some indication, in case you want to start
writing some code or anything in this area.
Cheers,
--
- Harald Welte <laforge at gnumonks.org> http://laforge.gnumonks.org/
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