C H A P T E R 19
• Provide an overview of technologies and applications of integrated voice/data networking.
• Outline the differences between the various voice/data integration technologies, and tell when each
should be used.
• Understand the specific protocols involved in voice/data networking.
• List specific network engineering challenges and solutions associated with the integration of voice
Voice/Data Integration Technologies
Voice/data integration is important to network designers of both service providers and enterprise.
Service providers are attracted by the lower-cost model—the cost of packet voice is currently estimated
to be only 20 to 50 percent of the cost of a traditional circuit-based voice network. Likewise, enterprise
network designers are interested in direct cost savings associated with toll-bypass and tandem switching.
Both are also interested in so-called “soft savings” associated with reduced maintenance costs and more
efficient network control and management. Finally, packet-based voice systems offer access to newly
enhanced services such as Unified Messaging and application control. These, in turn, promise to increase
the productivity of users and differentiate services.
Integration of voice and data technologies has accelerated rapidly in recent years because of both supply-
and demand-side interactions. On the demand side, customers are leveraging investment in network
infrastructure to take advantage of integrated applications such as voice applications. On the supply side,
vendors have been able to take advantage of breakthroughs in many areas, including standards,
technology, and network performance.
Many standards for interoperability for voice signaling have finally been ratified and matured to the
point of reasonable interoperability. This reduces the risk and costs faced by vendors offering
components of a voice/data system, and it also reduces the risk to consumers. Standards such as H.323