What is an Organizationally Unique Identifier (OUI)/”company_id”?
An OUI / “company_id” is a 24-bit globally unique assigned number referenced by various standards. For example, the OUI is used in the family of 802 LAN standards: Ethernet, Token Ring, etc. The OUI is usually concatenated with another 24 bits that are assigned by that Organization in order to make a 48-bit number that is unique to a particular piece of hardware, to make it possible to uniquely address that hardware. For example, the Ethernet MAC Address is such a 48-bit number, unique to one particular Ethernet interface. The OUI is usually concatenated with 24 or 40 bits to form an EUI-48 or an EUI-64. There are other uses of the OUI however, such as its use as a company identifier in the SNAP protocol.
