Possibility to use INET socket for external MNCC

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Luca Valtulina valtulina.luca at gmail.com
Mon Mar 31 15:34:57 UTC 2014


> 1) the MNCC interface carries both voice and signalling.  For signalling
>    you would like something that resembles TCP/SCTP/DCCP, but for the
>    voice you would only like UDP semantics.  Choosing either a reliable
>    protocol for voice frames or an unrealiable protocol for signalling
>    is calling for lots of trouble and will not happen.  So it would have
>    to  be multiple sockets.
>

Currently I am establishing RTP sockets for voice (from jolly/testing
branch) while a TCP/IP socket is used for signaling. So yes MNCC socket is
used only for signaling (I though also about the possibility of using it as
a "backup" socket in case RTP fails but then the reliable vs unreliable
issue pops up)


> 2) I don't think the current protocol is endian/alignment safe.  By
>    runnign it over a unix domain socket we basically enforce that both
>    programs on the MNCC side will run on the same architectuer and not
>    cause any problems.  If you run it over a network, making that
>    assumption is false.
>

The endianness can be carried in the payload of any packet to make it safer
or it can be exchanged upon socket setup for instance in the
MNCC_SOCKET_HELLO message.
Currently I am carrying the size of the sent signaling message in order to
distinguish between gsm_mncc and gsm_mncc_rtp (for now). I did it more as a
try than everything but I thought it was a waste to send 840 bytes of data
when gsm_mncc_rtp messages are only 24 bytes long!


> Will you be working on implementing this?
>

I might need a certain amount of guidance due to my lack of experience.

Luca
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