Convergence of telecommunications and computing to networking models for integrated services and applications

This paper gives a snapshot of the convergence of the telecommunications and computer industries to a common vision of networking models for an integrated services information infrastructure meeting the stringent requirements of multimedia applications. First we summarize the requirements and elements of such an infrastructure and introduce a networking model that is framed into four layers: interconnection (bearer), internetworking, interoperability (middleware), and application. Then, we offer a review of the classical telecommunications networking model, the current status of asynchronous transfer mode (ATM) multimedia networking features, and the ongoing activities for fostering evolution of telecommunications networks to enhance control, management, and service delivery. An overview of the current Internet network architecture follows, presenting the recent achievements and the evolving networking protocols to cope with real-time multimedia applications. As described in this paper, the schemes for integrating Internet protocols (IPs) and ATM resource reservation protocols, which address an efficient resource utilization and quality of service guarantee in broadband networks, fall into the first two lower architectural layers, which are the foundation of network computing and communications services. In particular, we present a summary description of the comparative features of both IP and ATM protocol approaches, and we report on current proposals for provisioning IP on ATM networks. Last, we discuss trends in middleware services, including the emerging technology of transportable computation and intelligent agents. Interoperability of heterogeneous networked systems is based on an agreed distributed application encoding and computation environment, thus pushing the key capability of the layered networking architecture up into the middleware layer.