1 EXHIBIT 21.1 GLOBAL TELESYSTEMS, INC. LIST OF SUBSIDIARIES NAME JURISDICTION GTS European Telecommunications Corp. Delaware Netcom Holding Limited United Kingdom Netcom Internet Ltd. United Kingdom GTS Slovakia s.r.o. Slovakia Global TeleSystems Europe B.V. Netherlands Global TeleSystems Europe Holdings B.V. Netherlands Global TeleSystems (Nederland) BV Netherlands Swift Global Netherlands BV Netherlands Interaktieve Media Services BV Netherlands IMS Plus Beheer BV Netherlands Ebone North America, Inc. Delaware GTS Carrier Services (Spain) S.L. Spain GTS Carrier Services (Switzerland) GmbH Switzerland GTS Transatlantic Limited Ireland GTS Network (Ireland) Ltd. Ireland GTS TransAtlantic Holdings Ltd. Bermuda GTS Network Services (Belgium) B.V.B.A. Belgium Ebone Broadband Services Ltd. Ireland Ebone (Germany) GmbH Germany GTS Carrier Services (France) Sarl France GTS Carrier Services (Italy) s.r.l. Italy GTS Carrier Services (Denmark) Aps Denmark GTS Business Services (Portugal) LDA Portugal Ebone (Nederland) B.V. Netherlands GTS Carrier Services (Sweden) AB Sweden GTS Carrier Services (UK) Limited United Kingdom Ebone A/S Denmark Global TeleSystems (Denmark) AS Denmark GTS Carrier Services (Czech) s.r.o. Czech Republic GTS Carrier Services (Slovakia) sro Slovakia Global TeleSystems (Norge) AS Norway Global TeleSystems (Sverige) AB Sweden Global TeleSystems (Austria) GmbH Austria GTS Italia Srl Italy GTS Carrier Services, Inc. Delaware NetSource Europe asa Norway Global TeleSystems Group Norge AS Norway GTS Danmark AS Denmark GTS Benelux BV Netherlands 2 Global TeleSystems (Luxembourg) SARL Luxembourg Westcom Gesellschaft fur Telekommunikation GmbH Germany GTS Business Services (Ireland) Ltd. Ireland Global TeleSystems (Belgium) S.A. Belgium Global TeleSystems (Europe) Limited United Kingdom GTS Access Services (UK) Limited United Kingdom Global TeleSystems (Property) Ltd. United Kingdom Esprit Telecom Networks, Ltd. United Kingdom GTS Business Services (UK) Ltd. United Kingdom Global TeleSystems (UK) Limited United Kingdom Esprit Telecom Holdings Ltd. United Kingdom Esprit Telecom Management Ltd. Jersey Esprit Telecom Europe B.V. Netherlands Global TeleSystems Holdings GmbH Germany Global TeleSystems (Deutschland) GmbH Germany Global TeleSystems Technical Services GmbH Germany Global TeleSystems Netzwerk Management GmbH Germany Global TeleSystems Netzwerk GmbH & Co.KG Germany Global TeleSystems (Espana) SA Spain Esprit Telecom France SA France GTS Omnicom SA France GTS Business Services (Switzerland) SA Switzerland GTS-Hungaro, Inc. Delaware GTS Hungary Telecommunications Ltd. Hungary GTS Central European Holding and Advisory JSC Hungary DataNet Telecom Ltd. Hungary GTS-Poland, Inc. Delaware GTS-Czech, Inc. Delaware GTS Czech a.s. Czech Republic GTS CzechCom s.r.o. Czech Republic Golden Telecom, Inc. Delaware