Configuring Audio Features843The Opus codec supports various audio bandwidths, defined as follows:Abbreviation Audio Bandwidth Sample Rate (Effective)NB (narrowband) 4 kHz 8 kHzMB (medium-band) 6 kHz 12 kHzWB (wideband) 8 kHz 16 kHzSWB (super-wideband) 12 kHz 24 kHzFB (fullband) 20 kHz 48 kHzNoteThe following table summarizes the supported audio codecs on IP phones:Codec Algorithm Reference Bit Rate SampleRatePacketizationTimeG722 G.722 RFC 3551 64 Kbps 16 Ksps 20msPCMA G.711 a-law RFC 3551 64 Kbps 8 Ksps 20msPCMU G.711 u-law RFC 3551 64 Kbps 8 Ksps 20msG729 G.729 RFC 3551 8 Kbps 8 Ksps 20msG726-16 G.726 RFC 3551 16 Kbps 8 Ksps 20msG726-24 G.726 RFC 3551 24 Kbps 8 Ksps 20msG726-32 G.726 RFC 3551 32 Kbps 8 Ksps 20msG726-40 G.726 RFC 3551 40 Kbps 8 Ksps 20msG723_53/G723_63 G.723.1 RFC 35515.3 Kbps6.3 Kbps8 Ksps 30msiLBC iLBC RFC 395215.2 Kbps13.33 Kbps8 Ksps 20ms30msopus opus RFC 671616 Kbps20 Kbps8 Ksps16 Ksps20msNote The network bandwidth necessary to send the encoded audio is typically 5~10% higher than thebit rate due to packetization overhead. For example, a two-way G.722 audio call at 64 Kbpsconsumes about 135 Kbps of network bandwidth.The SIP-T40P/T40G/T23P/T23G/T21(P) E2/T19(P) E2 IP phones support using WB for opusencoding; and using NB, MB, WB, SWB and FB for opus decoding.The SIP-T54S/T52S/T48S/T46S/T42S/T41S/T27G IP phones support using WB (default) or NB foropus encoding; and using NB, MB, WB, SWB and FB for opus decoding.
