Applications; Make Calls Via Internet Telephony Service Provider; Make Calls Via Ip-Pbx; Figure 1 Internet Telephony Service Provider Application - ZyXEL Communications V300 Series User Manual

Chapter 1 Introducing the V300

1.2 Applications

Here are some examples of how you can use your V300.

1.2.1 Make Calls via Internet Telephony Service Provider

In a home or small office environment, you can use the V300 to make and receive
VoIP telephone calls through an Internet Telephony Service Provider (ITSP).
The following figure shows a basic example of how you make a VoIP call through
an ITSP. In this example, you make a call from your V300 (A in the figure), which
sends the call through your modem or router (B) to the Internet and the ITSP's
SIP server (C). The VoIP call server forwards calls to PSTN (Public Switched
Telephone Network) phones through a trunking gateway (D) to phones on the
PSTN network (E). The VoIP call server also forwards calls to IP phones (F)
through the Internet.

Figure 1 Internet Telephony Service Provider Application

1.2.2 Make Calls via IP-PBX

If your company has an IP-PBX (Internet Protocol Private Branch Exchange), you
can use the V300 to make and receive VoIP telephone calls through it.
In this example, you make a call from your V300 (A in the figure), which sends it
to the IP-PBX. The IP-PBX forwards calls to PSTN phones (B) on the PSTN
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V300 Series User's Guide