7.4. VoIP

In the world of telecom, VoIP is still a relatively new concept. For the century or so prior to VoIP, the only way to connect your site to the PSTN was through the use of circuits provided for that purpose by your local telephone company. VoIP now allows for connections between endpoints without the PSTN having to be involved at all (although in most VoIP scenarios, there will still be a PSTN component at some point, especially if there is a traditional E.164 phone number involved).

7.4.1. PSTN Termination

Until VoIP totally replaces the PSTN, there will be a need to connect calls from VoIP networks to the public telephone network. This process is referred to as termination. What it means is that at some point a gateway connected to the PSTN needs to accept calls from the VoIP network and connect them to the PSTN network. From the perspective of the PSTN, the call will appear to have originated at the termination point.