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.
When Y=12, the default value is 97.
(only applicable to SIP-T4X IP phones)
For SIP-T21P/T19P IP phones:
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 102.