PDF of this tutorial
Definition
Voice-data consolidation is the transmission of both voice and data over a single packetized communications network. It combines the circuit-switched voice network with the routed packet data network to achieve efficiencies in technology and reduce equipment costs. While the possibilities of having a single packetized network to handle voice and data have always been enticing, the technology required to accomplish the goal efficiently was simply not available. Specifically, the delays incurred by processing packets inside the network were tolerable for delay-insensitive data applications but were unacceptable for delay-sensitive applications such as voice. However, advances in technology address this deficiency. Consequently, there is a growing interest in consolidating voice and data traffic on what will ultimately be a single, unified, packetized network from end to end.
Overview
This tutorial examines the reasons for separate networks and the advantages to be gained from consolidating voice and data traffic. It explains what the technical requirements are to achieve consolidation—specifically, data networks must be more reliable with a higher quality of service (QoS) if they are to be suitable for delay-sensitive applications such as voice.
Advantages exist both for service providers and end users in a consolidated network in terms of initial cost, maintenance, and support. Consolidation will enable new services that will appeal to both.
The major packet voice technologies are voice over asynchronous transfer mode (ATM), voice over frame relay, and voice over Internet protocol (VoIP). Of these, frame relay is transitional; ATM will stay in the backbone as a long-haul transit mode; and Internet protocol (IP) will ultimately be the end-to-end voice transport method. The current switched voice network will stay in place for at least a decade, slowly replaced by packetized voice. Early consolidation will take place on the wide-area networks that access the public switched telephone network (PSTN).
Small and medium-sized businesses will play a key role in the adoption of converged voice and data, as will new applications that go beyond the notion that “voice rides for free” over a packetized network.
