DINSTAR DAG2000-4S(GE) is a high-performance GSM VoIP Gateway designed for seamless GSM-to-VoIP communication. With 4 SIM slots, SIP support, and enterprise-grade reliability, it is ideal for businesses, telecom operators, and call centers. https://dinstarindia.com/product/dag2000-4sge-fxs-analog-voip-gateway/