In network design, the gap between theory and practice is woefully broad. This book narrows it, comprehensively and critically examining current network design models and methods. You will learn where mathematical modeling and algorithmic optimization have been under-utilized. At the opposite extreme, you will learn where they tend to fail to contribute to the twin goals of network efficiency and cost-savings. Most of all, you will learn precisely how to tailor theoretical models to make them as useful as possible in practice.Throughout, the authors focus on the traffic demands encountered in the real world of network design. Their generic approach, however, allows problem formulations and solutions to be applied across the board to virtually any type of backbone communication or computer network. For beginners, this book is an excellent introduction. For seasoned professionals, it provides immediate solutions and a strong foundation for further advances in the use of mathematical modeling for network design. Written by leading researchers with a combined 40 years of industrial and academic network design experience. Considers the development of design models for different technologies, including TCP/IP, IDN, MPLS, ATM, SONET/SDH, and WDM. Discusses recent topics such as shortest path routing and fair bandwidth assignment in IP/MPLS networks. Addresses proper multi-layer modeling across network layers using different technologies—for example, IP over ATM over SONET, IP over WDM, and IDN over SONET. Covers restoration-oriented design methods that allow recovery from failures of large-capacity transport links and transit nodes. Presents, at the end of each chapter, exercises useful to both students and practitioners.

This book provides a practical guide to flow-aware networking (FAN), one of the most promising new quality-of-service architectures for the Future Internet. The latest concepts are examined in detail, including coverage of approximate flow-aware networking. The scope and evolution of the debate on network neutrality is also discussed. Topics and features: provides a broad survey of flow-oriented approaches and solutions based on the concept of flows; presents a range of mechanisms for improving transmission performance of streaming flows under congestion; illustrates how problems caused by congestion may be solved in a multilayer environment, proposing new methods for enhancing transmission in wired-wireless FAN; analyzes aspects of fair transmission in FAN, reviewing algorithms that improve transmission of streaming flows during network failures; describes the implementation aspects of the cross-protect router; concludes each chapter with review questions, with answers provided at the end of the book.

The book presents a comprehensive view on Flow-Aware Networking. It starts with a brief overview of the known QoS architectures based on the concept of a flow. Then, the original FAN concept is presented, along with its variations proposed by the authors. The next chapter covers a very valuable feature of the FAN architecture, namely its ability to assure net neutrality. The chapters that follow will discuss, in detail, a variety of issues making the FAN concept implementable, including congestion control, fairness, resilience to failures, service differentiation and degradation. The final chapter presents the test implementation of the FAN router, including the environment used and performance tests. Chapters are supplemented with problems to solve, along with their solutions. The pedagogical character of the book is supported by a number of illustrative examples contained in most of the chapters. At the end of the book, a glossary of the key terms is included, along with a comprehensive bibliography. Flow-based traffic management is currently becoming a mainstream. There is plenty of Quality of Service (QoS) techniques based on flows. Software-Defined Networking with its dominant protocol OpenFlow also follows this trend. Flow-Aware Networking (FAN) is a promising QoS architecture. Information on FAN can be found in various research papers. It is, therefore highly scattered. This book gathers practically all relevant information regarding FAN and puts it together. Quality of Service assurance is one of the key challenges of today’s Internet. The existing approaches to provide QoS do not meet expectations of network operators, managers and users although numerous efforts in this area have been reported. One of the most promising concepts is the Flow-Aware Network (FAN). FAN can play a key role in assuring the net neutrality, smoothly combining interests of all the involved parties. The authors of the proposal have been involved in FAN research practically since its inception at the start of the 21st century. The book reports the wide experiences the authors accumulated in the subject area during the work on common FAN-related projects conducted with the team of James Roberts that proposed the original FAN concept as well as other leading research groups in Europe and the USA. One of the aims of the book is to accompany courses taught by the authors.

This document considers algorithms for flow control in computer networks with fixed routing. The goal is to establish input rates, for each source-destination pair, that satisfy a particular fairness criterion. Described are several algorithms in which the input rates are calculated based on controls established by the links of the network. These controls are updated iteratively, using feedback information from the network. It is shown that the rates thus calculated converge to the desired values when the links are assumed to update synchronously, and without feedback delay. A model for asynchronous operation with delay is given, and we demonstrate for this model that the input rates calculated by the synchronous algorithms may fail to converge. We show how to modify the algorithms, by the introduction of an update protocol and by using more of the available feedback information, so that convergence of the rates is guaranteed. The author extends the model for asynchronous computation developed by Bertsekas to get some results relating to general asynchronous distributed algorithms with update protocols. These results are used to give an alternate proof of the correct operation of one of the flow control algorithms. A computer program is developed to simulate the flow control algorithms for a voice packet network. The simulation results indicate that the algorithms behave as expected for a network with static loads. However, when input loads change in imitation of real conversations, the control algorithms do not adapt fast enough to control the flows effectively. (Author).