Voice Over Packet in Next Generation Networks: An Architectural Framework
Document Number SR-4717
Issue Number 01
Issue Date Jan 1999
ABSTRACT: The network of the future will be dominated by data, and Next Generation Networks (NGN) are being built for this purpose. At the heart
of NGN is Voice Over Packet (VOP), a packet-switched architecture that includes Voice Over Internet Protocol (VOIP), Asynchronous
Transfer Mode (ATM), and Frame Relay. In such packet-based environments, voice, data, fax, and video will be run over a single
network. The result will be network and operations cost efficiencies and an increase in carrier revenues through the creation of new
This Special Report (SR), SR-4717, explains the essential elements needed to build VOP networks. It provides a comprehensive
framework for the support of voice and other narrowband services over packet-based Networks. The VOP network that is discussed in this
document places significant emphasis on interoperability, scalability, and seamless interworking with the Public Switched Telephone
Network (PSTN). Such issues will be important for the VOP solution to be widely deployed.
This document is organized into 7 sections:
Section 1 presents introductory and background information, and discusses the motivation for Voice Over Packet.
Section 2 presents an overview of the current industry and standards activities on VOP, and discusses the need for VOP Generic
Section 3 identifies characteristics of a VOP network, such as network services, network capabilities, as well as its
relationship with the Next Generation Network.
Section 4 describes the high-level VOP architecture framework, together with illustration of the call flows and identification
of GRs needed for VOP.
Section 5 discusses the functionality of the significant components of a VOP network.
Section 6 presents the Operations and Maintenance framework for VOP and the major issues involved.
Section 7 discusses the migration strategies for various existing networks toward the VOP network discussed, and the migration
beyond VOP and toward NGN.