The article proposes an approach to the development of a methodology for increasing the efficiency of the functioning of special purpose electronic communications systems, especially the electronic communications system of the State Border Guard Service of Ukraine. The State Border Service of Ukraine is a subject of integrated border management. Information and communication systems, in particular, the information and communication system of border control are actively used in the operational and service activities of the State Border Guard Service to ensure the performance of the assigned functions. The technical basis for the transmission of information in the information and communication system is the system of electronic communications. The electronic communications system of the State Border Guard Service of Ukraine is built in the form of a complex network topology of the “star” type and uses the Transmission Control Protocol/Internet protocol (TCP/IP) stack for data transmission and, mainly, static routing, therefore, it does not provide the automatic recovery in the event of a violation of the existing route. Thus, for a certain time, a separate segment of the electronic communications system does not transmit information, as a result of which violations may occur at the state border. In the existing methods for evaluating the effectiveness of the functioning of the electronic communications system, such indicators as performance, stability, reliability of transmission, safety of data transmission are used. But those methods do not take into account the indicator of the dependence of tasks on the network. The study proposes to develop a methodology that would take into account the specified indicator of operational and service activity dependence in the system of indicators of the effectiveness of the electronic communications system. After entering into the system of efficiency indicators of the electronic communications system for special purposes, the operational and service activity efficiency indicator is proposed to calculate the updated efficiency of the electronic communications system when applying one or another routing protocol, network topology options and choose the best one. Key words: State Border Guard Service of Ukraine; integrated information and communication system “Hart”; information and communication system; operational and service activity; electronic communications system.