G.711: A-law, µ-qaw, 64 kbps
G.721: ADPCM, 32 kbps
G.722: 48/56/64 kbps
G.723: ADPCM? 24/40 kbps
G.723.1: ADPCM? 5.3/6.4 kbps
G.728: hyprid/CELP, 16 kbps (computing intensive, only slightly better than GSM)
G.729:

H.261: video compression >= 64 kbps
H.263: video compression < 64 kbps


H.323: Multimedia conferencing over packet switched networks (video/audio conferencing). Often used for Voice over IP.
