Various embodiments are directed toward a system and method pertaining to an interface device for provisioning Internet Protocol (IP) communications to be established for base station equipment that employ proprietary device specific protocols. In a conversion mode, a fixed station interface (FSI) translates between a V.24 High-Level-Data-Link Control (HDLC) protocol used for external data connections on base station equipment to a Voice-Over-Internet-Protocol (VOIP) open-standard protocol. In an autonomous mode, the FSI establishes a connection to at least one base station or other FSI automatically without the involvement of a dispatch console. Upon being deployed in First Responder communications networks (that use legacy base station equipment), the FSI provisions for the retention of existing installed base station equipment while providing a low-cost solution to support VOIP communications interconnectivity and reliability, thereby enhancing the effectiveness and safety of the First Responder systems.