CVoiceTonePlanIndexOrZero
This textual convention uniquely identifies the voice tone plan to be used in a voice DS0 group. The value of 0 means the default tone plan specified in the media gateway (the value of cMediaGwCcCfgDefaultTonePlanId) to be used. A value greater than 0 means the tone plan specified by the index of the cvtcTonePlanTable to be used (same as cvtcTonePlanId).