Bharat Sanchar Nagam Limited Abbreviated as BSNL is a telecommunication company having headquartered in New Delhi. It was incorporated on 15 September, 2000. It provides telecom services with ICT applications in urban and rural areas. This telecommunication system plays a major role in the e-governance projects. BSNL also provides three types of Internet access services namely Prepaid Dial-up connection, Postpaid Netone and DataOne as BSNL Broadband. It uses the FTTH (Fiber To The Home) technology for providing unlimited bandwidth. BSNL is India’s oldest communication service provider having customer base of 93.29 million till june,2015 It is one of the leading public sector units providing various telecommunication services in comprehensive range in India. BSNL also offers value added services like Free Phone Service. This attached presentation will make you understand the various technologies and networking concepts that are used by this largest telecommunication company i.e. TDMA, VoIP, Cellular system and Circuit Switching.