An OpenVox GSM Gateway is a communication device that bridges traditional GSM networks and modern VoIP (Voice over Internet Protocol) systems. It enables businesses to make and receive calls, send SMS messages, and route communication efficiently while reducing costs. With support for multiple SIM cards, these gateways are ideal for handling high volumes of traffic. They offer features like SIP integration, least-cost routing, and API support, making them versatile for both small and large-scale deployments.