VoIP Codec and Bandwidth
Cisco has a handy table
that compares quality (subjective) with bandwidth based on most of the popular codecs used by SIP VoIP ATAs today.
Codec | BR | NEB |
G.711 | 64 Kbps | 87.2 Kbps |
G.729 | 8 Kbps | 31.2 Kbps |
G.723.1 | 6.4 Kbps | 21.9 Kbps |
G.723.1 | 5.3 Kbps | 20.8 Kbps |
G.726 | 32 Kbps | 55.2 Kbps |
G.726 | 24 Kbps | 47.2 Kbps |
G.728 | 16 Kbps | 31.5 Kbps |
iLBC | 15 Kbps | 27.7 Kbps |
BR = Bit rate
NEB = Nominal Ethernet Bandwidth (one direction)