Yealink SIP-T2 SERIES Administrator's Manual page 827

Configuring Audio Features
Permitted
Parameters Default
Values
When Y=5, the default value is 9;
When Y=6, the default value is 106;
When Y=7, the default value is 103;
When Y=8, the default value is 104;
When Y=9, the default value is 102;
When Y=10, the default value is 105;
When Y=11, the default value is 107;
When Y=12, the default value is 121;
When Y=13, the default value is 122;
When Y=14, the default value is 123;
When Y=15, the default value is 124;
For SIP-T48G/T46G/T42G/T41P/T29G/CP860:
When Y=1, the default value is 0;
When Y=2, the default value is 8;
When Y=3, the default value is 4;
When Y=4, the default value is 4;
When Y=5, the default value is 18;
When Y=6, the default value is 9;
When Y=7, the default value is 106;
When Y=8, the default value is 103;
When Y=9, the default value is 104;
When Y=10, the default value is 102;
When Y=11, the default value is 105;
For SIP-T40P/T27P/T23P/T23G/T21(P) E2/T19(P) E2:
When Y=1, the default value is 0;
When Y=2, the default value is 8;
When Y=3, the default value is 18;
When Y=4, the default value is 9;
When Y=5, the default value is 106;
When Y=6, the default value is 103;
When Y=7, the default value is 104;
When Y=8, the default value is 102;
When Y=9, the default value is 105;
Example:
account.1.codec.1.rtpmap = 0
805