ABSTRACT
Voice communication is in the midst of an evolution toward
network convergence. Over the past several decades, the
coalescence of voice and data through the circuit-based,
voice-centric public-switched telephone network (PSTN)
has been limited. Interconnected networks exist today,
each maintaining its own set of devices, services, service
levels, skill sets, and security standards. These networks
anticipate the inevitable and ongoing convergence onto
packet-or cell-based, data-centric networks primarily built
for the Internet. Recent deregulation changes and cost sav-
ings, as well as the potential for new media applications and
services, are now driving a progressive move toward voice
over some combination of asynchronous transfer mode
(ATM), internet protocol (IP), and multi-protocol label
switching (MPLS). This new-generation network aims to
include novel types of telephony services that utilize packet-
switching technology to receive transmission efficiencies
while also allowing voice to be packaged in more standard
data applications. New security models that include encryp-
tion and security services are necessary in telecommunica-
tion devices and networks.
