In this report i will outline telecommunications authorities, types of connectivity, network services, the devices used and modes of data communications. The report will also describe transmission media, standards for data communications and data communications protocol parameters. It will also show an analysis of uses of data communications and network services, determining the devices, mode, transmission rate and protocol parameters.For communicating today you have to have certain standards these are the telecommunications standard setting authorities, and public telecommunications authorities The ISO / OSI model is the International standards Organisation/ Open system Interconnection layered architecture that defines how computers and networks should interact. This group was founded in 1946 and has issue more than 5000 standards on a wide range of areas. Its purpose is to promote the development of standardisation and related activities to facilitate international exchange of goods and services. Standards have been made to cover items from screw threads to solar energy’sThis is the AMERICAN NATIONAL STANDARDS INSTITUTE organisation which specifies computer and software standards, including those of high level programming languages. They are a non profit government federation of standards – making and standards using organisations. It has a wide range of members which include professional societies, trade associations, government and regulatory bodies, industrial companies and consumer groups. ANSI publishes national standards but does not develop them, standards are developed by other groups that are accredited to develop standards for ANSI consideration. A lot of this work is done by the Institute of Electric and Electronics Engineers (IEEE), who developed the IEEE 802 local area networks standards.