This attribute indicates the number of VCCs supported for the VPI
Zero VCC Space. The VCI values of these VCCs range from 0 to
(numVccsForVpiZero - 1). For Apc-based cards, the maximum
value is 16384. For CQC-based cards, the maximum value is
16128.
To override the system default, see the AtmIf ConnMap Ov attribute
numVccsForVpiZero.