IANA manages the DNS Root Zone (assignments of ccTLDs and gTLDs), as well as the .int registry, and the .arpa zone.
IANA coordinates the global IP and AS number space, and allocates these to Regional Internet Registries.
IANA review process. ICANN is conducting a number of reviews regarding how the IANA functions are performed. These reviews are being conducted between late 2012 and mid-2013, and we welcome feedback from the community.