The DVG-2001S supports the SIP protocol, which is widely deployed by VoIP providers on the market. It also supports the most popular audio CODEC to ensure compatibility and voice quality. It comes with one FXS port to connect to the existing analog telephone and one Fast Ethernet port to connect to the broadband router. It is the ideal VoIP telephone adapter solution that will help VoIP service providers or resellers with all of the required attributes to grow and retain customers by delivering a robust and consistent VoIP solution.