reply to dnoyeB
Re: [Anveo] G711U vs. G729 g.711 sounds the best, but it consumes the most bandwidth ~11KB/sec
g.729 sounds acceptable, but the bandwidth it consumes is much less ~4KB/sec
So basically if your connection can handle g.711 without dropouts or other issues, keep it as it is.
Use g.729 only if you have limited bandwidth or voice quality problems with g.711.