PSTN Connectivity - Real-Time Communication on AWS

PSTN Connectivity

Voice over IP (VoIP) solutions use PSTN Gateways and SIP Trunks to connect with legacy PSTN networks.

PSTN Gateway

The public switched telephone network (PSTN) Gateway converts the signaling (between SIP and SS7) and media (between RTP and time division multiplexing [TDM] using CODEC transcoding). PSTN Gateways always sit at the edge close to the PSTN network.

SIP Trunk

In a SIP Trunk, the enterprise does not terminate its calls onto a TDM (SS7 based) network, but rather the flows between enterprise and telco remain over IP. Most of the SIP Trunks are established by using SBCs. The enterprise must agree on the predefined security rules from telco, such as allowing a certain range of IP addresses, ports, and so on.