[Spce-user] mismatch codecs in certain calls

[Joan Cifre (ibred)]

Hi all,
we are experiencing problems with certain calls. The call is stablished 
but we speakers can't hear each other. This is happening just with 
certain calls and with certain peerings, so I'm almost sure this is not 
a NGCP problem. However, I think this is due to a bad codec negotiation. 
I can see this line i certaing calls

P-RTP-Stat: 
PS=828,OS=16560,PR=446,OR=71360,PL=0,JI=0,LA=0,DU=9,EN=G729a,DE=G711a'

Does it means that one server is sending streams with G729a codec and 
the other one with G711a codec? Which one decides which codec use if 
both are in the list?
Thanks for the support.
Joan