About International Standards Standardizing Organizations
The following Table shows the major international standardizing organizations. In the telecommunications field, the CCITT was established in 1865 and then switched to the ITU in 1993 as an international organization within the UN. The ISO is popularly known, but the IEC was founded earlier.

Major International Standardizing Organizations
Name Fields Founded
ITU Telecommunications 1865 (1993)
IEC Electrical, electronic and related technologies 1906
ISO Other than the above 1947
Note      ITU :  International Telecommunication Union
IEC :  International Electrotechnical Commission
ISO :  International Organization for Standardization

Each country has a sole representative to each body. In Japan, the Ministry of Internal Affairs and Communications (Information and Communications Policy Bureau) is the representative to ITU and the JISC (Japanese Industrial Standardization Committee within the Ministry of Economy, Trade and Industry) is the representative to IEC and ISO.
Technical Committees (TCs) carry out the standards work of the IEC or ISO in their respective scopes. In Japan, representatives to respective TCs are set up under JISC, e.g., a deliberative body for IEC and undertaking body for ISO.