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.