Internet protocol transport of PSTN-to-PSTN telephony services

摘要

A system for transporting public switched network (PSTN) terminated signaling across an Internet protocol (IP) network includes a gateway between the PSTN and the IP network. The gateway receives a telephony signaling message from the PSTN and determines if the telephony signaling message maps to an IP signaling message. If the telephony signaling message does not map to an IP signaling message, the gateway packages the telephony signaling message in a special IP signaling message for transport over the IP network. If the gateway receives a special IP signaling special message, the gateway unpackages the telephony signaling message from the special message for transport over the PSTN. If the gateway receives DTMF signals from the PSTN, the gateway translates the DTMF signals to digits and packages the digits in a special IP signaling message for transport over the IP network. The gateway also packages the DTMF signals in an IP media transport protocol message for transport over the IP network.