o The first four bits of a WWN identify the Name Assignment Authority (NAA) and the address format defined by that NAA. Currently, the Institute of Electrical and Electronics Engineers (IEEE) is the only defined NAA.
o The definitions of the remaining 60 bits are determined by the address format defined by the NAA. The IEEE defines four address
formats: The Standard format defines a 48-bit address field that contains a IEEE 802.1A Universal LAN MAC Address (ULA).
The Extended format defines a 48-bit IEEE 802.1A ULA and provides an additional 12 bits for a vendor-specific ID (VSID).
The Registered format defines a 24-bit Company_ID and a 36- bit VSID.