 The MA-M assignment block provides both 220 EUI-48 identifiers and 236 EUI-64 identifiers (that means first 28 bits are IEEE assigned bits).The first 24 bits of the assigned MA-M block are an OUI assigned to IEEE that will not be reassigned, so the MA-M does not include assignment of an OUI.Addresses can either be "universally administered addresses" (UAA) or "locally administered addresses" (LAA).