IANA (Internet Assigned Numbers Authority) is the organization under the Internet Architecture Board (IAB) of the Internet Society that, under a contract from the U.S. government, has overseen the allocation of Internet Protocol addresses to Internet service providers (ISPs). IANA also has had responsibility for the registry for any "unique parameters and protocol values" for Internet operation. These include port numbers, character sets, and MIME media access types.
Partly because the Internet is now a global network, the U.S. government has withdrawn its oversight of the Internet, previously contracted out to IANA, and lent its support to a newly-formed organization with global, non-government representation, the Internet Corporation for Assigned Names and Numbers (ICANN). ICANN has now assumed responsibility for the tasks formerly performed by IANA.