User Manual

Yealink Skype for Business HD IP Phones Administrator Guide
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Parameter
Permitted Values
Default
Web User Interface:
None
Phone User Interface:
None
Audio Codecs
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 audio codec that the Skype for Business phone uses to establish a call should be supported
by the SIP server. When placing a call, the Skype for Business phone will offer the enabled audio
codec list to the server and then use the audio codec negotiated with the called party according
to the priority.
The following table lists the audio codecs supported by each phone model:
Skype for Business phone
Model
Supported Audio Codecs
Default Audio Codecs
T48G/T46G/T42G/T41P
G722, PCMA, PCMU, G729,
G726-16, G726-24, G726-32,
G726-40, iLBC, G723_53,
G723_63
G722, PCMA, PCMU,
G729
T40P
G722, PCMA, PCMU, G729,
G726-16, G726-24, G726-32,
G726-40, iLBC
G722, PCMA, PCMU,
G729
The following table summarizes the supported audio codecs on Skype for Business phones:
Codec
Algorithm
Reference
Bit Rate
Sample
Rate
Packetization
Time
G722
G.722
RFC 3551
64 Kbps
16 Ksps
20ms
PCMA
G.711 a-law
RFC 3551
64 Kbps
8 Ksps
20ms
PCMU
G.711 u-law
RFC 3551
64 Kbps
8 Ksps
20ms
G729
G.729
RFC 3551
8 Kbps
8 Ksps
20ms
G726-16
G.726
RFC 3551
16 Kbps
8 Ksps
20ms
G726-24
G.726
RFC 3551
24 Kbps
8 Ksps
20ms
G726-32
G.726
RFC 3551
32 Kbps
8 Ksps
20ms