This object determines the size and bit pattern that is compared to the traffic frame at the location specified by the offset type and starting at the offset location in order to produce a result. The size of the mask must be equivalent to the size of the filter defined in ibmVlanUDSWFilter. The value of 1 in a mask bit location has the effect of making a comparison of the mask to the traffic frame significant. The value of a zero in a mask bit location has the effect of making the comparison of the mask with the traffic frame a 'don't care'. The octets in this object are transmitted in most significant byte first order. There is no default value and this mask must be specified when creating a UDSW VLAN in the ibmVlanConfTable.