Yealink SIP-T4X Administration Manual page 208

To configure dual headset via web user interface:
1. Click on Features->General Information.
2. Select the desired value from the pull-down list of Dual-Headset.
3. Click Confirm to accept the change.
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 default codecs used on IP phones are summarized in the following table:
Codec Algorithm
PCMA G.711 a-law
PCMU G.711 u-law
G729 G.729
G722 G.722
In addition to the codecs introduced above, IP phones also support codecs: G723_53,
G723_63, G726-16, G726-24, G726-32, G726-40, GSM and iLBC. Codecs and priorities of
Bit Rate Sample Rate
64 Kbps 8 Ksps
64 Kbps 8 Ksps
8 Kbps 8 Ksps
64 Kbps 16 Ksps
Configuring Audio Features
Packetization Time
20ms
20ms
20ms
20ms
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