G.711ALaw is a companding standard using non-linear encoding and decoding to provide pulse code modulation mainly of voice frequencies with the A-law variant algorithm.
G.711MuLaw is a companding standard using non-linear encoding and decoding to provide pulse code modulation mainly of voice frequencies with the μ-law variant algorithm. It provides higher compression than A-Law, with higher distorion for smaller packets.
G.729 is a compression standard with linear compression for voice with low bandwith requirements, suitable for voip applications where bandwith conservation is an issue. It divides 10ms packets for a 8kbit/s transmission rate.