Exhibit 21.1 Subsidiaries of the Registrant Jurisdiction of Subsidiary Incorporation - ---------- ------------------- Primus Telecommunications, Inc.............................. Delaware Primus Telecommunications, International, Inc. ............. Delaware Primus Telecommunications, Ltd.............................. United Kingdom Primus Telecommunications, de Mexico, S.A. de C.V. ......... Mexico Primus Telecommunications, Pty., Ltd. ...................... Australia Primus Telecommunications, (Australia) Pty., Ltd. (formerly known as Axicorp Pty., Ltd.)..................... Australia 3362426 Canada Inc. d/b/a Primus Canada........................................ Canada GlobalServe Communications, Inc. ........................... Ontario Primus Telecommunications, Netherlands B.V. ................ Netherlands Primus Telecommunications SA................................ France PTI GmbH.................................................... Germany Primus TeleCom A/S.......................................... Denmark Primus Telecommunications SA................................ Spain Primus Telecommunications AG................................ Switzerland Primus Telecommunications SRL............................... Italy Primus Telecommunications K.K. ............................. Japan Primus Japan K.K. .......................................... Japan Eclipse Data Services Pty., Ltd. ........................... Australia Hotkey Internet Services Pty., Ltd.......................... Australia Rate Reduction Center, Inc.................................. Florida Least Cost Routing, Inc. ................................... Florida Rockwell Communications Corporation......................... Florida Intex Telecommunications, Inc. ............................. South Carolina TresCom International, Inc. ................................ Florida TresCom Network Services, Inc............................... Florida TresCom U.S.A., Inc. ....................................... Florida Global Telephone Holding, Inc. ............................. U.S. Virgin Islands InterIsland Telephone Corp.................................. U.S. Virgin Islands The St. Thomas and San Juan Telephone Company, Inc. ........ U.S. Virgin Islands STSJ Overseas Telephone Company, Inc........................ Puerto Rico OTC Networks Assets, Inc. .................................. Puerto Rico Puerto Rico Telecom Corporation............................. New York STSJ Network Assets, Inc. .................................. U.S. Virgin Islands Telegroup Network Services Denmark ApS...................... Denmark TeleContinent, S.A. ........................................ France Telegroup Deutschland GmbH.................................. Germany Telegroup Network Services Deutschland GmbH................. Germany Telegroup Italia S.r.l. .................................... Italy Telegroup Nederland B.V. ................................... Netherlands Telegroup International B.V. ............................... Netherlands Global Access Pty. Ltd. .................................... South Africa Telegroup Network Services S.A. ............................ Switzerland Telegroup (U.K.) Limited.................................... United Kingdom Corporate Networks Limited.................................. United Kingdom South East Telecom Limited.................................. United Kingdom Phone Centre Communications (Service) Limited............... United Kingdom Telegroup Japan Kabushiki Kaisha............................ Japan iPRIMUS.com., Inc. ......................................... Delaware London Telecom Network, Inc................................. Canada TCP/IP GmbH................................................. Germany TouchNet GmbH............................................... Germany CP Telecom AG............................................... Germany