dc.description.abstract
Convergence is undoubtedly revolutionizing communications technologies and businesses, thereby merging networks of different types and origins. The future of telecommunications depends on the success of combining old and new solutions to serve new customer needs. It is obvious that a new breed of technologies emerges to solve the fundamental differences between traditional telecommunications and Internet technologies, and to integrate present and future content services. The characteristics of these technologies are far beyond what has been currently deployed: they are based on open platforms, multi-interfaced, distributed in nature, componentised yet integrated, interoperate autonomously and spontaneously, and they are reliable and scalable performance-wise. It is neither easy nor convenient to try to predict what the dominant designs of the era of converged and next generation networks (NGN) are and will be, but some trends can be observed as will be described in our book. Clearly, the most important trend of all is IP integration and its emerging technologies. This integration takes place mainly in the service and switching layers, and thus accelerates the adoption of leading edge data communication technologies such as gigabit Ethernet, WDM, ATM, and VoIP. Another trend is the overall integration of access and transport network interfaces: there are various different appliances and thus access networks, but they are tightly integrating to each network operator's terabit core transport network. At the same time it is not only networks and services which are converging. Appliances from different vendors are increasingly multi-featured including voice and productivity applications, wireless data connectivity an other sophisticated capabilities. It is clear that there will be a further consolidation of technologies in this area. This book addresses IN, IP analysis, design, and performance as well as their converging architecture for network services and signaling. It encompasses work on the integration of two different kind of networks (e.g., circuit-switched and packet-switched). This integration has started from simple interworking and interoperation of functions. And, it will result in a fully converged network. The goal of this work is the design of the architecture for seamless interworking between different elements of the converged network (e.g., different access networks), which is necessary for the support of new hybrid services. This book also examines current approaches towards the integration of signaling between packet-switched and circuit-switched networks. Until now convergence between the two networks has for the most part taken place in the transport and signaling layers. Signaling interworking architectures however cater for the specific class of voice services and do not provide a generic platform for service interworking with distributed services on the Internet. Through the adaptation of Parlay APIs a way is foreseen for homogenization of voice services over both Internet and PSTN while allowing the installed IN infrastructure to be used also for Internet telephony services and for service interworking between voice services and open distributed services in the Internet. The book describes a layered service architecture that can be used as a platform for service interworking. What is the service - it is some abstractive framework, or the way in which we see its performance. What is the application - it is a way in which we implement abstraction into something real (e.g., software). Application is not program - it is an imaginary framework implemented (built) into software. So, how to create software of a service (application)? How to put abstraction into the framework? The first step is - divide abstraction onto blocks - what we want to have and what we want to see in this application, e.g., create a framework. The second step is - see what the real network/system can offer us, e.g., if it is able to support this application. And, the third step - is an analytical model. It shows and explains the operation of the application in the network, e.g. how the network support the service(s). To build proper and valuable models is the first, the main, and the most important task of every network services designer. The same was done in our research. According to that, our goal was not to model, analyze, and simulate processors' speed values from different vendors. For that purpose, we created an analytical model, which properly explains operation and interworking of various services in converged networks. And, how big the values of l or m will be - milliseconds, microseconds, or nanoseconds is not important if the balance equation lambda/mu ; 1 (e.g., system stability) is satisfied.
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