Implementation and Evaluation of a Mobile Tetherless VoIP/PSTN Gateway
Jui-Hao Chiang, Tzi‐cker Chiueh · 2009
A voice-over-IP (VoIP) gateway bridges IP-based packet-switched networks (i.e. Internet) with public circuitswitched telephone networks (i.e. PSTN). The key building block of a VoIP gateway is a telephony card that interfaces with the PSTN and converts signals from the PSTN to bits that can be manip