<Tr> <Th> Subsidiaries </Th> <Td> KDDI R&D Labs KDDI Network & Solutions Kokusai Cable Ship Okinawa Cellular Telephone KDDI America KDDI Global </Td> </Tr> <Tr> <Th> Website </Th> <Td> www.kddi.com </Td> </Tr> <P> KDDI Corporation (KDDI 株式 会社, KDDI Kabushiki Gaisha) (TYO: 9433) is a Japanese telecommunications operator formed in October 1, 2000 through the merger of DDI Corp . (Daini - Denden Inc .), KDD (Kokusai Denshin Denwa) Corp., and IDO Corp . It has its headquarters in the Garden Air Tower in Iidabashi, Chiyoda, Tokyo . </P> <P> KDDI provides mobile cellular services using the "au by KDDI" brand . ISP network and solution services are provided under the au one net brand, while "au Hikari" is the name under which long - distance and international voice and data communications services and Fiber to the Home (FTTH) services are marketed . ADSL broadband services carry the brand name "ADSL One", and IP telephony over copper is branded as "Metal Plus". </P>

When were the ntt and kdd telephone companies established