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In this paper, a cost effective voice network using the VoIP (Voice over Internet Protocol) technology is described. The connections of Private Branch Exchanges (PBXs) to a VoIP network, to the PSTN (Public Switched Telephone Network) and to the ISDN (Integrated Services Digital Networks) are considered from the technological point of view; the VoIP protocol architecture, the VoIP standards, quality of service (QoS) issues in the VoIP networks are discussed, traffic load and channel capacity calculations of a sample application are presented. It is emphasized that government organizations, universities, big companies, banks and other establishments, having units or campuses situated in different sites in the same city or in different cites can make use of the VoIP technology to reduce their telephone costs. Although the VoIP technology is ready for such applications, there is an argument in Turkey whether or not VoIP is legal even for intranet applications. It is mentioned that the regulations concerning VoIP in Turkey need to be clarified or rearranged to stop the argument and enable the use of VoIP Technology.