Individual Address Block
The Individual Address Block (IAB) is a block of identifiers that is formed by concatenating a 24-bit Organizationally Unique Identifier (OUI) that is owned by the IEEE Registration Authority with an additional 12-bit extension identifier that is assigned by the IEEE Registration Authority and then reserving an additional 12 bits for use by the assignee. The resulting 48-bit identifier uniquely identifies the assignee of the IAB and provides 4096 unique EUI-48 numbers for use by the organization that purchased the IAB. The assignee may create unique identifiers by concatenating a 12-bit extension identifier that is assigned by the organization that purchases the IAB in the bit positions occupied by the 12 additional bits mentioned previously. The purpose of the IAB is to allow organizations to purchase smaller blocks of identifiers.
The IEEE Registration Authority distinguishes between IABs and OUI-36 values. Both are 36-bit values which may be used to generate EUI-48 values, but IABs may not be used to generate EUI-64 values.
Example of EUI-48 created within an IAB: An EUI-48 identifier is formed by combining the 36-bit IEEE assigned IAB base value with a 12-bit extension identifier assigned by the organization – e.g., if the IEEE assigned IAB base value is FF-FF-FF-FF-F0-00 and the 12-bit extension identifier is hhh16, then the EUI-48 value generated by combining these two numbers is FF-FF-FF-FF-Fh-hh.
Note:There are also IAB based CDI-40 sequences that are formed by combining the 36-bit IEEE assigned IAB base value with the 4-bit extension identifier assigned by the organization – e.g., if the IEEE assigned IAB base value is FF-FF-FF-FF-F0-00 and the 4-bit extension identifier is 0h16, then the CDI-40 value generated by combining these two numbers is FF-FF-FF-FF-Fh.
Read more about this topic: Organizationally Unique Identifier
Famous quotes containing the words individual, address and/or block:
“It is the individual only who is timeless. Societies, cultures, and civilizations—past and present—are often incomprehensible to outsiders, but the individual’s hungers, anxieties, dreams, and preoccupations have remained unchanged through the millennia.”
—Eric Hoffer (1902–1983)
“If you have any information or evidence regarding the O.J. Simpson case, press 2 now. If you are an expert in fields relating to the O.J. Simpson case and would like to offer your services, press 3 now. If you would like the address where you can send a letter of support to O.J. Simpson, press 1 now. If you are seeking legal representation from the law offices of Robert L. Shapiro, press 4 now.”
—Advertisement. Aired August 8, 1994 by Tom Snyder on TV station CNBC. Chicago Sun Times, p. 11 (July 24, 1994)
“It is, in both cases, that a spiritual life has been imparted to nature; that the solid seeming block of matter has been pervaded and dissolved by a thought; that this feeble human being has penetrated the vast masses of nature with an informing soul, and recognised itself in their harmony, that is, seized their law. In physics, when this is attained, the memory disburthens itself of its cumbrous catalogues of particulars, and carries centuries of observation in a single formula.”
—Ralph Waldo Emerson (1803–1882)