The DAG1000-4S is an active analog telephone adapter that provides unconnected connections between IP-based telephony networks and legacy (POTS) networks, fax machines and PBX systems. With the standard SIP protocol, it is compatible with leading IMS / NGN platforms and IP systems designed for IP telephony. It offers 4 FXS ports, IP fax and flexible dialing systems. Providing a high-quality and reliable voice over-IP service, this device is suitable for call centers, small and medium enterprises, SoHO and residential users.