T Runking - ZyXEL Communications Prestige 2602HWL-D3A Support Manual

Prestige 2602HWL-D3A Support Notes
Trunking
VoIP trunking connects an IP network (like the Internet) and the Public Switched Telephone
Network (PSTN). PSTN includes the world's circuit-switched telephone network which is
composed of fixed and mobile telephones.
VoIP trunking allows you to create VoIP links which PSTN (Public Switched Telephone Network)
callers can use to:
* Make phone calls via the Internet - Make a PSTN call to the ZyXEL Device and it forwards the
call to any SIP based VoIP phone.
* Save on long distance calls - The ZyXEL Device creates a VoIP link which can be used to
connect to a PSTN phone in another country, province, region and so on.
Similarly, VoIP callers can:
* Make calls to PSTN subscribers at reduced cost - Connect to the ZyXEL Device via VoIP and
the ZyXEL Device forwards the call to a PSTN phone.
Creating a link over the IP network requires two VoIP devices. VoIP trunking scenarios vary
depending on how the VoIP devices work together and how they receive or forward PSTN calls.
The following sections describe the details of VoIP trunking.
159
All contents copyright (c) 2007 ZyXEL Communications Corporation.