Outline — full article in progress
This page has the structure and introduction. The full article is being written by the network team. In the meantime, ask us directly.
G.711 sounds better and uses more bandwidth; G.729 sounds slightly worse and uses much less. That's the short version. This article puts real numbers on the bandwidth with packet overhead, shows the quality difference in MOS terms, and explains why transcoding between the two often costs more than it saves.