Cologne-base QSC AG is a nationwide telecommunications provider in Germany with its own DSL network. It supplies a comprehensive portfolio of broadband communication solutions such as leased lines in various bandwidths to voice and data services right through to custom enterprise networks. The company caters to the enterprise and residential markets. Its services are available in more than 70 German cities. It is a member of the TecDAX 30, Germany's 30 leading public technology companies.