The CCITT(the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union.CCITT is responsible for studying technical,operating and tariff questionsand issuing Recommendationson them with a view to standarding spis oo a worldwide basis.The Plenary Assemblyof CCITT which meets every four years,establishes the topicsforstudy and approves Recammendations prepared by its Study Groups.