User Manual - Configuration Guide (Volume 3)
Versatile Routing Platform Chapter 1
VoIP Configuration
1-1
Chapter 1 VoIP Configuration

1.1 VoIP Overview

VoIP is the abbreviation of Voice over IP. What we often called IP phone is a typical
application of the VoIP. The application of VoIP in router makes it possible that the voice
service can be implemented through the IP network, including the plain phone ser vice
and fax.
VoIP is implemented through voice packet. In VoIP, the digital signal processor (DSP)
splits the voice signals into frames and stores them in packets for transmission. VoIP is
mainly a software solution. It needs the support of voice port board added to the router.
At the beginning of 1995, a kind of software product that could m ake toll calls on
Internet was available for the first time, and this phone service implemented o n Internet
was called Internet phone, this was the early form of the IP phone. Through five years
of development, the IP phone has been developed all over the world as a n e w t ype of
phone service, which poses as a great threat to the plain phone service.
The development of IP telephone benefits from the promotion of technology and the
drive of market.
The years of technological accumulation makes the technology of transfo rming voice
into IP technology increasingly mature and practical. At the same time, the high-speed
development of the integrated circuits (IC) causes the price of the cor e com ponent of
the IP phone—DSP going down greatly, these factors contribute to the technical
possibility for the promotion of the IP telephone.
The drive of market benefits is also a significant reason for the rapid development of the
IP phone. Using the VoIP network composed of IP voice gateway and other device, we
can bypass the toll calls to the data network, thus greatly reducing large bi ll for toll
expenses and benefits the subscribers.
Through the development from the beginning of 1990s till now, the IP phone has
developed form the IP software period to the IP gateway period. And also the c urrent
VoIP application has developed from the simple PC products with voice service to the
telecommunication service with multiple services and f unctionality such as high
reliability, high quality voice, fax and data transmission.
At present, IP gateway is used to interconnect PSTN (Public Switching Telephone
Network) and the Internet, so as to mature the technology of PC to phone, phone to PC
and phone to phone. In addition, voice quality is greatly improve d an d th e c om m ercial
requirements can be satisfied.