Making Calls Via Ip-Pbx; Figure 2 Internet Telephone Service Provider Application - ZyXEL Communications PRESTIGE 2602R Series User Manual

Prestige 2602R Series User's Guide
The following figure shows a basic example of how you would make a VoIP call through an
ITSP. You use your analog phone (A in the figure) and the Prestige (B) changes the call into
VoIP. The Prestige then sends your call through your modem or router (C) to the Internet and
the ITSP's SIP server. The VoIP call server forwards calls to PSTN phones (F) through a
trunking gateway (E) to the PSTN network. The VoIP call server forwards calls to IP phones
(G) through the Internet.

Figure 2 Internet Telephone Service Provider Application

1.3.3 Making Calls via IP-PBX

If your company has an IP-PBX (Internet Protocol Private Branch Exchange), you can use the
Prestige to make and receive VoIP telephone calls through it.
In this example, you use your analog phone (A in the figure) and the Prestige (B) changes the
call into VoIP and sends it to the IP-PBX. The IP-PBX forwards calls to PSTN phones (C) to
the PSTN network. The IP-PBX forwards calls to IP phones (D) through an IP network (this
could include the Internet).
41 Chapter 1 Getting To Know Your Prestige