Mobile Ad Hoc Networks

Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms

Equal cost multipath routing in IP networks

IP verkkojen palveluntarjoajat ja loppukäyttäjät vaativat yhä tehokkaampia ja parempilaatuisia palveluita, mikä vaatii tuotekehittäjiä tarjoamaan hienostuneempia liikennesuunnittelumenetelmiä verkon optimointia ja hallintaa varten. IS-IS ja OSPF ovat standardiratkaisut hoitamaan reititystä pienissä ja keskisuurissa pakettiverkoissa. Monipolkureititys on melko helppo ja yleispätevä tapa parantaa kuorman balansointia ja nopeaa suojausta tällaisissa yhden polun reititykseen keskittyvissä verkoissa. Tämä diplomityö kirjoitettiin aikana, jolloin monipolkureititys toteutettiin Tellabs-nimisen yrityksen 8600-sarjan reitittimiin. Tärkeimpiä kohtia monipolkureitityksen käyttöönotossa ovat lyhyimmän polun algoritmin muokkaukseen ja reititystaulun toimintaan liittyvät muutokset ohjaustasolla sekä kuormanbalansointialgoritmin toteutus reitittimen edelleenkuljetustasolla. Diplomityön tulokset sekä olemassa oleva kirjallisuus osoittavat, että kuormanbalansointialgoritmilla on suurin vaikutus yhtä hyvien polkujen liikenteen jakautumiseen ja että oikean algoritmin valinta on ratkaisevan tärkeää. Hajakoodaukseen perustuvat algoritmit, jotka pitävät suurimman osan liikennevuoista samalla polulla, ovat dominoivia ratkaisuja nykyisin. Tämän algoritmityypin etuna on helppo toteutettavuus ja kohtuullisen hyvä suorituskyky. Liikenne on jakautunut tasaisesti, kunhan liikennevuoiden lukumäärä on riittävän suuri. Monipolkureititys tarjoaa yksinkertaisen ratkaisun, jota on helppo konfiguroida ja ylläpitää. Suorituskyky on parempi kuin yksipolkureititykseen perustuvat ratkaisut ja se haastaa monimutkaisemmat MPLS ratkaisut. Ainoa huolehdittava asia on linkkien painojen asettaminen sillä tavalla, että riittävästi kuormantasauspolkuja syntyy.Increasing efficiency and quality demands of services from IP network service providers and end users drive developers to offer more and more sophisticated traffic engineering methods for network optimization and control. Intermediate System to Intermediate System and Open Shortest Path First are the standard routing solutions for intra-domain networks. An easy upgrade utilizes Equal Cost Multipath (ECMP) that is one of the most general solutions for IP traffic engineering to increase load balancing and fast protection performance of single path interior gateway protocols. This thesis was written during the implementation process of the ECMP feature of Tellabs 8600 series routers. The most important parts in adoption of ECMP are changes to shortest path first algorithm and routing table modification in the control plane and implementation of load balancing algorithm to the forwarding plane of router. The results of the thesis and existing literature prove, that the load balancing algorithm has the largest affect on traffic distribution of equal cost paths and the selection of the correct algorithm is crucial. Hash-based algorithms, that keep the traffic flows in the same path, are the dominating solutions currently. They provide simple implementation and moderate performance. Traffic is distributed evenly, when the number of flows is large enough. ECMP provides a simple solution that is easy to configure and maintain. It outperforms single path solutions and competes with more complex MPLS solutions. The only thing to take care of is the adjustment of link weights of the network in order to create enough load balancing paths

Some new localized quality of service models and algorithms for communication networks. The development and evaluation of new localized quality of service routing algorithms and path selection methods for both flat and hierarchical communication networks.

The Quality of Service (QoS) routing approach is gaining an increasing interest in the Internet community due to the new emerging Internet applications such as real-time multimedia applications. These applications require better levels of quality of services than those supported by best effort networks. Therefore providing such services is crucial to many real time and multimedia applications which have strict quality of service requirements regarding bandwidth and timeliness of delivery. QoS routing is a major component in any QoS architecture and thus has been studied extensively in the literature. Scalability is considered one of the major issues in designing efficient QoS routing algorithms due to the high cost of QoS routing both in terms of computational effort and communication overhead. Localized quality of service routing is a promising approach to overcome the scalability problem of the conventional quality of service routing approach. The localized quality of service approach eliminates the communication overhead because it does not need the global network state information. The main aim of this thesis is to contribute towards the localised routing area by proposing and developing some new models and algorithms. Toward this goal we make the following major contributions. First, a scalable and efficient QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated. Second, we have developed a path selection technique that can be used with existing localized QoS routing algorithms to enhance their scalability and performance. Third, a scalable and efficient hierarchical QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated

Localised Routing Algorithms in Communication Networks with Quality of Service Constraints. Performance Evaluation and Enhancement of New Localised Routing Approaches to Provide Quality of Service for Computer and Communication Networks.

The Quality of Service (QoS) is a profound concept which is gaining increasing attention in the Internet industry. Best-effort applications are now no longer acceptable in certain situations needing high bandwidth provisioning, low loss and streaming of multimedia applications. New emerging multimedia applications are requiring new levels of quality of services beyond those supported by best-effort networks. Quality of service routing is an essential part in any QoS architecture in communication networks. QoS routing aims to select a path among the many possible choices that has sufficient resources to accommodate the QoS requirements. QoS routing can significantly improve the network performance due to its awareness of the network QoS state. Most QoS routing algorithms require maintenance of the global network¿s state information to make routing decisions. Global state information needs to be periodically exchanged among routers since the efficiency of a routing algorithm depends on link-state information accuracy. However, most QoS routing algorithms suffer from scalability due to the high communication overhead and the high computation effort associated with maintaining accurate link state information and distributing global state information to each node in the network. The ultimate goal of this thesis is to contribute towards enhancing the scalability of QoS routing algorithms. Towards this goal, the thesis is focused on Localised QoS routing algorithms proposed to overcome the problems of using global network state information. Using such an approach, the source node makes routing decisions based on the local state information for each node in the path. Localised QoS routing algorithms avoid the problems associated in the global network state, like high communication and processing overheads. In Localised QoS routing algorithms each source node maintains a predetermined set of candidate paths for each destination and avoids the problems associated with the maintenance of a global network state by using locally collected flow statistics and flow blocking probabilities.Libya's higher educatio

Mobile Ad Hoc Networks

Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms

Simple and stable dynamic traffic engineering for provider scale ethernet

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia InformáticaThe high speeds and decreasing costs of Ethernet solutions has motivated providers’ interest in using Ethernet as the link layer technology in their backbone and aggregation networks. Provider scale Ethernet offers further advantages, providing not only an easy to manage solution for multicast traffic, but also transparent interconnection between clients’ LANs. These Ethernet deployments face altogether different design issues, requiring support for a significantly higher number of hosts. This support relies on hierarquization, separating address and virtual network spaces of customers and providers. In addition, large scale Ethernet solutions need to grant forwarding optimality. This can be achieved using traffic engineering approaches. Traffic engineering defines the set of engineering methods and techniques used to optimize the flow of network traffic. Static traffic engineering approaches enjoy widespread use in provider networks, but their performance is greatly penalized by sudden load variations. On the other hand, dynamic traffic engineering is tailored to adapt to load changes. However, providers are skeptical to adopt dynamic approaches as these induce problems such as routing instability, and as a result, network performance decreases. This dissertation presents a Simple and Stable Dynamic Traffic Engineering framework (SSD-TE), which addresses these concerns in a provider scale Ethernet scenario. The validation results show that SSD-TE achieves better or equal performance to static traffic engineering approaches, whilst remaining both stable and responsive to load variations

Datacenter Traffic Control: Understanding Techniques and Trade-offs

Datacenters provide cost-effective and flexible access to scalable compute and storage resources necessary for today's cloud computing needs. A typical datacenter is made up of thousands of servers connected with a large network and usually managed by one operator. To provide quality access to the variety of applications and services hosted on datacenters and maximize performance, it deems necessary to use datacenter networks effectively and efficiently. Datacenter traffic is often a mix of several classes with different priorities and requirements. This includes user-generated interactive traffic, traffic with deadlines, and long-running traffic. To this end, custom transport protocols and traffic management techniques have been developed to improve datacenter network performance. In this tutorial paper, we review the general architecture of datacenter networks, various topologies proposed for them, their traffic properties, general traffic control challenges in datacenters and general traffic control objectives. The purpose of this paper is to bring out the important characteristics of traffic control in datacenters and not to survey all existing solutions (as it is virtually impossible due to massive body of existing research). We hope to provide readers with a wide range of options and factors while considering a variety of traffic control mechanisms. We discuss various characteristics of datacenter traffic control including management schemes, transmission control, traffic shaping, prioritization, load balancing, multipathing, and traffic scheduling. Next, we point to several open challenges as well as new and interesting networking paradigms. At the end of this paper, we briefly review inter-datacenter networks that connect geographically dispersed datacenters which have been receiving increasing attention recently and pose interesting and novel research problems.Comment: Accepted for Publication in IEEE Communications Surveys and Tutorial

New quality of service routing algorithms based on local state information. The development and performance evaluation of new bandwidth-constrained and delay-constrained quality of service routing algorithms based on localized routing strategies.

The exponential growth of Internet applications has created new challenges for the control and administration of large-scale networks, which consist of heterogeneous elements under dynamically changing traffic conditions. These emerging applications need guaranteed service levels, beyond those supported by best-effort networks, to deliver the intended services to the end user. Several models have been proposed for a Quality of Service (QoS) framework that can provide the means to transport these services. It is desirable to find efficient routing strategies that can meet the strict routing requirements of these applications. QoS routing is considered as one of the major components of the QoS framework in communication networks. In QoS routing, paths are selected based upon the knowledge of resource availability at network nodes and the QoS requirements of traffic. Several QoS routing schemes have been proposed that differ in the way they gather information about the network state and the way they select paths based on this information. The biggest downside of current QoS routing schemes is the frequent maintenance and distribution of global state information across the network, which imposes huge communication and processing overheads. Consequently, scalability is a major issue in designing efficient QoS routing algorithms, due to the high costs of the associated overheads. Moreover, inaccuracy and staleness of global state information is another problem that is caused by relatively long update intervals, which can significantly deteriorate routing performance. Localized QoS routing, where source nodes take routing decisions based solely on statistics collected locally, was proposed relatively recently as a viable alternative to global QoS routing. It has shown promising results in achieving good routing performance, while at the same time eliminating many scalability related problems. In localized QoS routing each source¿destination pair needs to determine a set of candidate paths from which a path will be selected to route incoming flows. The goal of this thesis is to enhance the scalability of QoS routing by investigating and developing new models and algorithms based on the localized QoS routing approach. For this thesis, we have extensively studied the localized QoS routing approach and demonstrated that it can achieve a higher routing performance with lower overheads than global QoS routing schemes. Existing localized routing algorithms, Proportional Sticky Routing (PSR) and Credit-Based Routing (CBR), use the blocking probability of candidate paths as the criterion for selecting routing paths based on either flow proportions or a crediting mechanism, respectively. Routing based on the blocking probability of candidate paths may not always reflect the most accurate state of the network. This has motivated the search for alternative localized routing algorithms and to this end we have made the following contributions. First, three localized bandwidth-constrained QoS routing algorithms have been proposed, two are based on a source routing strategy and the third is based on a distributed routing strategy. All algorithms utilize the quality of links rather than the quality of paths in order to make routing decisions. Second, a dynamic precautionary mechanism was used with the proposed algorithms to prevent candidate paths from reaching critical quality levels. Third, a localized delay-constrained QoS routing algorithm was proposed to provide routing with an end-to-end delay guarantee. We compared the performance of the proposed localized QoS routing algorithms with other localized and global QoS routing algorithms under different network topologies and different traffic conditions. Simulation results show that the proposed algorithms outperform the other algorithms in terms of routing performance, resource balancing and have superior computational complexity and scalability features.Umm AlQura University, Saudi Arabi

Overlay auxiliary routing: achieving near minimum delay routing solutions for overlay networks.

Zhang Li.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.Includes bibliographical references (leaves 71-74).Abstracts in English and Chinese.Abstract --- p.ii摘要 --- p.ivAcknowledgments --- p.vContents --- p.viChapter Chapter 1 --- Introduction --- p.1Chapter Chapter 2 --- Internet Routing and Performance Studies --- p.5Chapter 2.1 --- Border Gateway Protocol Version 4 (BGP4) --- p.5Chapter 2.2 --- Internet Performance Studies --- p.6Chapter 2.3 --- Improve Routing Performance --- p.8Chapter 2.3.1 --- Traffic Engineering --- p.8Chapter 2.3.2 --- Network-layer Techniques --- p.9Chapter 2.3.3 --- Minimum Delay Routing --- p.11Chapter Chapter 3 --- Overlay-based Techniques --- p.15Chapter 3.1 --- Content Distribution Network --- p.16Chapter 3.2 --- Relative Overlay Techniques --- p.16Chapter Chapter 4 --- Overlay Minimum Delay Routing --- p.19Chapter 4.1 --- Minimum Delay Routing in Overlay Network --- p.21Chapter 4.1.1 --- Problem Formulation --- p.21Chapter 4.1.2 --- Necessary and Sufficient Conditions for Distributed Computing --- p.25Chapter 4.1.3 --- Optimal Overlay Auxiliary Routing (00AR) Algorithm --- p.29Chapter 4.2 --- Performance Comparing with Optimal IP routing --- p.31Chapter Chapter 5 --- Sub-Optimal Overlay Auxiliary Routing Algorithm --- p.39Chapter 5.1 --- Approximation Conditions to Optimal Overlay Routing --- p.40Chapter 5.2 --- SOAR algorithm Overview --- p.44Chapter 5.3 --- Distributing Traffic over Multiple Paths --- p.49Chapter 5.3.1 --- Adaptive load Adjustment --- p.50Chapter 5.3.2 --- Per-flow Routing Control --- p.53Chapter 5.4 --- Discussion on Marginal Delay of an OAR Link --- p.55Chapter Chapter 6 --- Performance Evaluation of Sub-Optimal Overlay Auxiliary Routing --- p.57Chapter 6.1 --- Experiment Method Description --- p.57Chapter 6.2 --- Comparison of overall delay --- p.61Chapter 6.3 --- Effect of the Routing update interval parameters xx and yy --- p.64Chapter 6.4 --- Comparison of packet loss rate --- p.66Chapter 6.5 --- Comparison of potential maximum data transmission rate --- p.68Chapter 6.6 --- Stability of the OAR load-balancing heuristics algorithm --- p.69References --- p.71Appendix --- p.7