Yealink SIP-T2 SERIES Administrator's Manual page 869

Procedure
Configuration changes can be performed using the configuration files or locally.
Configuration File
Configure the codecs to use for SIP
account.
Parameters:
account.X.codec.Y.enable
account.X.codec.Y.payload_type
Configure the priority and rtpmap for
the enabled codec.
Parameters:
account.X.codec.Y.priority
<MAC>.cfg
account.X.codec.Y.rtpmap
Configure the sample rate for the
Opus codec.
Parameter:
account.X.codec.Y.para
Configure the ptime.
Parameter:
account.X.ptime
Configure the special audio codec
byte sequence.
<y0000000000xx>
Parameter:
.cfg
phone_setting.audio_codec_byte_orde
r.enable
Configuring Audio Features
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