This object specifies the payload type of the CODEC in
voice application as specified in RFC1890.
The values (0..95) are static payload type.
The values (96..127) are dynamic payload type and it is
specified dynamically through the control protocol during
call setup.
If more than one CODEC have the same payload type,
the CODEC with the highest preference (the lowest value of
cvapCodecConfigPreference) will be selected.