Deutsche Telekom AG, together with its subsidiaries, provides integrated telecommunication services worldwide.
Telefónica Deutschland Holding AG provides telecommunication and connectivity solutions to private and business customers in Germany.
United Internet AG, through its subsidiaries, operates as an Internet service provider.
1&1 Drillisch AG, together with its subsidiaries, operates as a telecommunications provider in Germany.
freenet AG provides telecommunication, radio and multimedia, mobile communications, mobile Internet, and digital lifestyle services in Germany.
QSC AG engages in the cloud, Internet of Things (IoT), consulting, telecommunications, and colocation businesses in Germany and internationally.
NFON AG provides cloud private branch exchange (PBX) services in Germany, Austria, Italy, the United Kingdom, and Spain.
ecotel communication ag operates as a telecommunications company in Germany.
Public Joint-Stock Company Ukrtelecom provides fixed line telephony and Internet services primarily in Ukraine.
TELES Aktiengesellschaft Informationstechnologien, together with its subsidiaries, provides telecommunication technologies and services for carriers and business customers in Germany and internationally.