Yealink SIP-T48G Administrator's Manual page 205

CODEC is an abbreviation of COmpress-DECompress, capable of coding or decoding a
digital data stream or signal by implementing an algorithm. The object of the algorithm
is to represent the high-fidelity audio signal with minimum number of bits while retaining
the quality. This can effectively reduce the frame size and the bandwidth required for
audio transmission.
The following table lists the audio codecs supported by each phone model:
Phone Model
G722, PCMU, PCMA, G729, G726-16,
SIP-T48G G726-24, G726-32, G726-40, iLBC,
G723_53, G723_63, GSM
G722, PCMU, PCMA, G729, G726-16,
SIP-T22(P) G726-24, G726-32, G726-40, iLBC,
G723_53, G723_63
The following table summarizes the supported audio codecs on IP phones:
Codec Algorithm
G722 G.722
PCMU G.711
u-law
PCMA G.711
a-law
G729 G.729
G726-16 G.726
G726-24 G.726
G726-32 G.726
G726-40 G.726
G723_53/
G.723.1
G723_63
iLBC iLBC
GSM GSM
Codecs and priorities of these codecs are configurable on a per-line basis. The attribute
"rtpmap" is used to define a mapping from RTP payload codes to a codec, clock rate
and other encoding parameters.
Supported Audio Codecs
Reference Bit Rate
RFC 3551 64 Kbps
RFC 3551 64 Kbps
RFC 3551 64 Kbps
RFC 3551 8 Kbps
RFC 3551 16 Kbps
RFC 3551 24 Kbps
RFC 3551 32 Kbps
RFC 3551 40 Kbps
5.3 Kbps
RFC 3951
6.3 Kbps
13.33 Kbps
RFC 3952
15.2 Kbps
RFC 3551 13 Kbps
Configuring Audio Features
Default Audio Codecs
G722, PCMU, PCMA,
G729
G722, PCMU, PCMA,
G729
Sample Rate
16 Ksps
8 Ksps
8 Ksps
8 Ksps
8 Ksps
8 Ksps
8 Ksps
8 Ksps
8 Ksps
8 Ksps
8 Ksps
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