The multicast group address that when combined with alaIgmpStaticSsmMapGrpPrefixLength gives the group prefix for this entry. The InetAddressType is given by the alaIgmpStaticSsmMapAddressType object. This address object is only significant up to alaIgmpStaticSsmMapGrpPrefixLength bits. The remainder of the address bits are zero. This is especially important for this index field which is part of the index of this entry. Any non-zero bits would signify an entirely different entry.