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242 Chapter 10

Figure 10-4
Dedicated access
to the Internet for
large organizations

Router ISP
T1
CO

Internet
Firewall

Enter the Packet-Switching World

To facilitate the integration and convergence of the voice and data
worlds, the industry quickly evolved to the idea of conducting all of
our business using the Internet protocol (IP). The terms that quickly
appeared were as follows:

Voice over IP (VoIP)
Video over IP
Fax over IP

Each of the industry segments was engulfed in a means of making
these real-time, time-sensitive applications work on the IP protocols
and creating an efficiency improvement in the circuit-switched net-
work by changing to a packet-switched architecture. We heard that
using a compressed voice conversation and a packet-switching mech-
anism, we could gain an 11- to 13-fold increase in the number of calls
that could be handled on the existing circuits in the long-distance
and local networks. The model was modified to reflect these changes
by creating a VoIP service and the protocols to support this new use