A mobile ad hoc network (MANET) is a collection of mobile platforms or nodes that come together to form a network capable of communicating with each other, without the help of a central controller. To avail the maximum potential of a MANET, it is of great importance to devise a routing scheme, which will optimize upon the performance of a MANET, given the high rate of random mobility of the nodes. In a MANET individual nodes perform the routing functions like route discovery, route maintenance and delivery of packets from one node to the other. Existing routing protocols flood the network with broadcasts of route discovery messages, while attempting to establish a route. This characteristic is instrumental in deteriorating the performance of a MANET, as resource overhead triggered by broadcasts is directly proportional to the size of the network. Bounded-dynamic source routing (B-DSR), is proposed to curb this multitude of superfluous broadcasts, thus enabling to reserve valuable resources like bandwidth and battery power. B-DSR establishes a bounded region in the network, only within which, transmissions of route discovery messages are processed and validated for establishing a route. All route discovery messages reaching outside of this bounded region are dropped, thus preventing the network from being flooded. In addition B-DSR also guarantees loop-free routing and is robust for a rapid recovery when routes in the network change.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2014. / Virtual worlds and massive multiplayer online games are amongst the most popular applications on the Internet. In order to host these applications a reliable architecture is required. It is essential for the architecture to handle high user loads, maintain a complex game state, promptly respond to game interactions, and prevent cheating, amongst other properties. Many of today’s Massive Multiplayer Online Games (MMOG) use client-server architectures to provide multiplayer service. Clients (players) send their actions to a server. The latter calculates the game state and publishes the information to the clients. Although the client-server architecture has been widely adopted in the past for MMOG, it suffers from many limitations. First, applications based on a client-server architecture are difficult to support and maintain given the dynamic user base of online games. Such architectures do not easily scale (or handle heavy loads). Also, the server constitutes a single point of failure. We argue that peer-to-peer architectures can provide better support for MMOG. Peer-to-peer architectures can enable the user base to scale to a large number. They also limit disruptions experienced by players due to other nodes failing. This research designs and implements a peer-to-peer architecture for MMOG. The peer-to-peer architecture aims at reducing message latency over the network and on the application layer. We refine the communication between nodes in the architecture to reduce network latency by using SPDY, a protocol designed to reduce web page load time. For the application layer, an event-driven paradigm was used to process messages. Through user load simulation, we show that our peer-to-peer design is able to process and reliably deliver messages in a timely manner. Furthermore, by distributing the work conducted by a game server, our research shows that a peer-to-peer architecture responds quicker to requests compared to client-server models.

A thesis submitted to the Faculty of Engineering, University of the '\Vitwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy / THIS STUDY identifies and evaluates factors that affect call connections in the South African public data networks, modelling these factors to aid data network planning. The research shows the relationship between the economic rank of each region served and the data communication resources required for that region. Moreover, it shows the resources required between regions. THE THRUST of this thesis is that the volume of cans from a region can be estimated from its economic ...k and more than 75% olthe variation in the volume of calls between regions can be explained using the ranks of the originating and terminating regions. To prove this, records of more than four million calls are accumulated for all regions of the South African packet switched data network. An appropriate filtering and aggregation method is developed. EXISTING growth models including the gravity model are separately examined. Based on probability and dimensional arguments, the Bell System growth model is selected. It is revealed that the success of this model depends on one premise being satisfied: this model tacitly anti implicitly assumes that the originating and terminating calls are statistically independent. RETURNING to the data network, it is found that the call connections (after filtering and aggregation) display dependence of destination on origin. Reasons for the dependence are discovered. Multiple linear regression reveals the nature of this dependence. Surprisingly, distance is not a factor. The importance of regional ranks and an inter-regional indicator variable are also discovered. FINALL Y, call volume from a node is shown to be directly linked with the weighted Gross Regional and Industrial Product of the region. This quantity, in tum, is inversely related to the rank of the region. Call connections are then modelled to be equal to the call connections within the first tanked region divided by the product of the originating region's rank and the terminating region's rank. This simple and economical model explains 76% of the variations that occur in call connections. It has proved its use by being included in the data transfer services product-line report. / Andrew Chakane 2018

Disruption-Tolerant Networks (DTNs) are the networks comprised of a set of wireless nodes, and they experience unstable connectivity and frequent connection disruption because of the limitations of radio range, power, network density, device failure, and noise. DTNs are characterized by their lack of infrastructure, device limitation, and intermittent connectivity. Such characteristics make conventional wireless network routing protocols fail, as they are designed with the assumption the network stays connected. Thus, routing in DTNs becomes a challenging problem, due to the temporal scheduling element in a dynamic topology. One of the solutions is prediction-based, where nodes mobility is estimated with a history of observations. Then, the decision of forwarding messages during data delivery can be made with that predicted information. Current prediction-based routing protocols can be divided into two sub-categories in terms of that whether they are probability related: probabilistic and non-probabilistic. This dissertation focuses on the probabilistic prediction-based (PPB) routing schemes in DTNs. We find that most of these protocols are designed for a specified topology or scenario. So almost every protocol has some drawbacks when applied to a different scenario. Because every scenario has its own particular features, there could hardly exist a universal protocol which can suit all of the DTN scenarios. Based on the above motivation, we investigate and divide the current DTNs scenarios into three categories: Voronoi-based, landmark-based, and random moving DTNs. For each category, we design and implement a corresponding PPB routing protocol for either basic routing or a specified application with considering its unique features. / Specifically, we introduce a Predict and Relay routing protocol for Voronoi-based DTNs, present a single-copy and a multi-copy PPB routing protocol for landmark-based DTNs, and propose DRIP, a dynamic Voronoi region-based publish/subscribe protocol, to adapt publish/subscribe systems to random moving DTNs. New concepts, approaches, and algorithms are introduced during our work. / by Quan Yuan. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Hua Cunqing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 53-56). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Congestion Control in the IP Network --- p.1 / Chapter 1.2 --- Quality of Service in the IP network --- p.2 / Chapter 1.3 --- Structure of Thesis --- p.3 / Chapter 2 --- Background --- p.4 / Chapter 2.1 --- TCP and Congestion Control --- p.4 / Chapter 2.1.1 --- Slow Start --- p.4 / Chapter 2.1.2 --- Congestion Avoidance --- p.5 / Chapter 2.1.3 --- "Fast Retransmit, Fast Recovery and Timeout" --- p.5 / Chapter 2.2 --- Active Queue Management --- p.7 / Chapter 2.3 --- Integrated Services and Differentiated Services --- p.8 / Chapter 3 --- The Fairness of TCP Vegas in Networks with Multiple Congested Gate- ways --- p.10 / Chapter 3.1 --- Introduction --- p.10 / Chapter 3.2 --- TCP Vegas and related works --- p.11 / Chapter 3.3 --- Analysis --- p.13 / Chapter 3.4 --- Simulation Results --- p.15 / Chapter 3.4.1 --- Throughput for different number of active cross connections --- p.16 / Chapter 3.4.2 --- Throughput for different number of flows in each connection --- p.17 / Chapter 3.4.3 --- Multiple congestion vs Single congestion --- p.17 / Chapter 3.5 --- Summary --- p.19 / Chapter 4 --- The Joint Congestion Control for TCP/IP Networks --- p.21 / Chapter 4.1 --- Background --- p.21 / Chapter 4.2 --- The Joint Congestion Control --- p.23 / Chapter 4.2.1 --- Path Load Reduction Factor --- p.23 / Chapter 4.2.2 --- The Congestion Control Algorithm --- p.24 / Chapter 4.2.3 --- Probing Interval --- p.26 / Chapter 4.2.4 --- Parameter Setting --- p.26 / Chapter 4.2.5 --- Encoding of R --- p.27 / Chapter 4.3 --- Simulation Results --- p.28 / Chapter 4.3.1 --- Congestion Window Behavior --- p.28 / Chapter 4.3.2 --- Throughput Stability --- p.31 / Chapter 4.3.3 --- Packet Loss Ratio --- p.31 / Chapter 4.3.4 --- Fairness Index --- p.32 / Chapter 4.3.5 --- Fairness in Multiple-hop Network --- p.32 / Chapter 4.3.6 --- Parameter Sensitivity --- p.33 / Chapter 4.3.7 --- Interaction between JCC and Reno flows --- p.35 / Chapter 4.4 --- Summary --- p.35 / Chapter 5 --- S-WTP : Shifted Waiting Time Priority Scheduling for Delay Differ- entiated Services --- p.37 / Chapter 5.1 --- Introduction --- p.37 / Chapter 5.2 --- Scheduling Algorithms for Delay Differentiated Services --- p.38 / Chapter 5.3 --- Shifted Waiting Time Priority Scheduling --- p.41 / Chapter 5.3.1 --- Local Update --- p.42 / Chapter 5.3.2 --- Global Update --- p.42 / Chapter 5.3.3 --- Computational overhead --- p.42 / Chapter 5.4 --- Simulation Results --- p.43 / Chapter 5.4.1 --- Microscopic View of Individual Packet Delay of S-WTP and WTP --- p.43 / Chapter 5.4.2 --- Delay Ratios in Different Timescales --- p.44 / Chapter 5.4.3 --- Effects of aggregate traffic and class load distribution on delay ratio --- p.44 / Chapter 5.4.4 --- Delay Ratios with More Classes --- p.48 / Chapter 5.5 --- Summary --- p.48 / Chapter 6 --- Conclusions --- p.50 / Chapter 6.1 --- Congestion Control --- p.50 / Chapter 6.2 --- Quality of Service Provision --- p.51 / Chapter 6.3 --- Final Remarks --- p.51

by Patrick C.K. Wu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 57-[59]). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Research Objectives --- p.2 / Chapter 1.2 --- Organization of the Thesis --- p.2 / Chapter 2 --- Background --- p.4 / Chapter 2.1 --- Reliable Multicasting --- p.4 / Chapter 2.2 --- Related Work --- p.5 / Chapter 2.2.1 --- RMTP --- p.5 / Chapter 2.2.2 --- RMP --- p.6 / Chapter 2.2.3 --- RAMP --- p.7 / Chapter 2.3 --- Multicast with Scalable Reliability (MSR) --- p.8 / Chapter 3 --- Traffic Shaping in MSR --- p.10 / Chapter 3.1 --- Single Queue System --- p.11 / Chapter 3.2 --- Scaling factor α --- p.12 / Chapter 4 --- Retransmission Scheme in MSR --- p.15 / Chapter 4.1 --- Packet Loss Detection and Requests for Retransmission at the Receivers --- p.17 / Chapter 4.2 --- Retransmission at the Sender --- p.19 / Chapter 4.3 --- Dynamic Adjustment of Retransmission Timeout Value --- p.22 / Chapter 4.4 --- Scaling Reliability using Transmit-Display Window --- p.29 / Chapter 5 --- NACK Implosion Prevention --- p.31 / Chapter 5.1 --- Electing a Representative Receiver --- p.32 / Chapter 5.2 --- Determining T --- p.33 / Chapter 5.3 --- Determining β --- p.34 / Chapter 6 --- Performance Study of MSR --- p.38 / Chapter 6.1 --- Performance Study of MSR in Simple Network Topologies --- p.39 / Chapter 6.2 --- Star Topology --- p.40 / Chapter 6.3 --- Tree Topology --- p.44 / Chapter 6.4 --- Exploring the use of MSR Gateway --- p.47 / Chapter 7 --- Conclusion and Future Work --- p.50 / Chapter 7.1 --- Future Work --- p.50 / Chapter 7.2 --- Conclusions --- p.51 / Chapter A --- MSR Packet Formats --- p.52 / Chapter A.1 --- MSR Fixed Header --- p.52 / Chapter A.2 --- MSR Audio Data Header --- p.54 / Chapter A.3 --- MSR NACK Packets --- p.55 / Bibliography --- p.57

Internet applications have varied Quality of Service (QoS) Requirements. Traditional applications such as FTP and email are throughput sensitive since their quality is primarily affected by the throughput they receive. There are delay sensitive applications such as streaming audio/video and IP telephony, whose quality is more affected by the delay. The current Internet however does not provide QoS support to the applications and treats the packets from all applications as primarily throughput sensitive. Delay sensitive applications can however sacrifice throughput for delay to obtain better quality. We present a Traffic Sensitive QoS controller (TSQ) which can be used in conjunction with many existing Active Queue Management (AQM) techniques at the router. The applications inform the TSQ enabled router about their delay sensitivity by embedding a delay hint in the packet header. The delay hint is a measure of an application's delay sensitivity. The TSQ router on receiving packets provides a lower queueing delay to packets from delay sensitive applications based on the delay hint. It also increases the drop probability of such applications thus decreasing their throughput and preventing any unfair advantage over throughput sensitive applications. We have also presented the quality metrics of some typical Internet applications in terms of delay and throughput. The applications are free to choose their delay hints based on the quality they receive. We evaluated TSQ in conjunction with the PI-controller AQM over the Network Simulator (NS-2). We have presented our results showing the improvement in QoS of applications due to the presence of TSQ.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Li Fengjun. / Thesis submitted in: July 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 83-84). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgments --- p.v / Table of Contents --- p.vi / List of Figures --- p.viii / List of Tables --- p.ix / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivations of this work --- p.1 / Chapter 1.2 --- Network Fairness Issue --- p.3 / Chapter 1.3 --- Our Contribution --- p.4 / Chapter 1.4 --- Organization of the Thesis --- p.5 / Chapter Chapter 2 --- Background of Fairness Index --- p.7 / Chapter 2.1 --- The Model --- p.7 / Chapter 2.2 --- Definitions of Fairness Index --- p.9 / Chapter 2.3 --- General Existence and Uniqueness Properties of Perfectly Fair Solution --- p.12 / Chapter 2.4 --- Properties in Specific Network Topologies --- p.16 / Chapter 2.4.1 --- Uniform Routing Networks --- p.16 / Chapter 2.4.2 --- Single Routing Node Networks --- p.20 / Chapter Chapter 3 --- Extension of the Fairness Index --- p.22 / Chapter 3.1 --- A Single Routing Node Network Example --- p.22 / Chapter 3.2 --- The Max-Min Fairness Index --- p.27 / Chapter 3.3 --- Von Neumann Equilibrium Index --- p.29 / Chapter Chapter 4 --- Distributed Low Bit Rate Algorithm --- p.36 / Chapter 4.1 --- Distributed Controller --- p.36 / Chapter 4.2 --- Convergence of the Low Bit Rate Distributed Algorithm --- p.39 / Chapter 4.3 --- Experiment Results --- p.49 / Chapter 4.4 --- Heuristic Iterative Algorithm --- p.53 / Chapter Chapter 5 --- Fairness Index Based Routing --- p.57 / Chapter 5.1 --- Routing Protocol Basics --- p.58 / Chapter 5.1.1 --- Static Routing and Dynamic Routing --- p.58 / Chapter 5.1.2 --- Routing Metrics --- p.59 / Chapter 5.1.3 --- Distance Vector and Link State --- p.60 / Chapter 5.1.4 --- Shortest Path Routing Algorithm --- p.62 / Chapter 5.2 --- Minimum Delay Routing --- p.63 / Chapter 5.3 --- Fairness Index Based Routing --- p.66 / Chapter 5.3.1 --- Problem Formulation --- p.66 / Chapter 5.3.2 --- Cost Function --- p.69 / Chapter 5.3.3 --- Implementing Fairness Index Based Routing --- p.71 / Chapter 5.3.4 --- Experiment and Analysis --- p.73 / Bibliography --- p.82

Feng, Guosen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 56-60). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background for Network Content Providers' Peering --- p.1 / Chapter 1.2 --- Literature Review --- p.5 / Chapter 2 --- A Static Baseline Model --- p.12 / Chapter 2.1 --- Content Qualities and Subscribing Fees --- p.12 / Chapter 2.2 --- Users' Utilities --- p.13 / Chapter 2.3 --- Providers' Coverages and Revenues --- p.14 / Chapter 2.4 --- Content Procurement Strategies --- p.16 / Chapter 2.5 --- The Peering and Bargaining of Providers --- p.16 / Chapter 2.5.1 --- Peering Agreement --- p.16 / Chapter 2.5.2 --- Change of Coverage --- p.17 / Chapter 2.5.3 --- Providers' Revenues --- p.18 / Chapter 2.5.4 --- Nash Bargaining Problem --- p.18 / Chapter 3 --- Impact of Dynamic Content --- p.23 / Chapter 3.1 --- Additional Investment for Dynamic Content --- p.24 / Chapter 3.1.1 --- Content Change --- p.24 / Chapter 3.1.2 --- Change of Coverage --- p.24 / Chapter 3.1.3 --- Providers' Revenue --- p.30 / Chapter 3.2 --- Finite Budget for Dynamic Content --- p.30 / Chapter 3.2.1 --- Content Change --- p.30 / Chapter 3.2.2 --- Change of Coverage --- p.30 / Chapter 3.2.3 --- Providers' Revenue --- p.35 / Chapter 4 --- Peeing in Dynamic Model --- p.36 / Chapter 4.1 --- Peering over T Time Slots --- p.37 / Chapter 4.1.1 --- "Content Change, Advertisement Sharing, and Payment ." --- p.37 / Chapter 4.1.2 --- Change of Coverage --- p.37 / Chapter 4.1.3 --- Providers' Revenue --- p.38 / Chapter 4.1.4 --- Nash Bargaining Problem --- p.38 / Chapter 4.2 --- Peering over One Time Slot --- p.45 / Chapter 4.2.1 --- "Content Change, Advertisement Sharing, and Payment ." --- p.45 / Chapter 4.2.2 --- Change of Coverage --- p.46 / Chapter 4.2.3 --- Providers' Revenue --- p.48 / Chapter 4.2.4 --- Nash Bargaining Problem --- p.49 / Chapter 5 --- Summary and Future Work --- p.53 / Bibliography --- p.56 / Chapter A --- Proof of Optimal Peering Strategy --- p.61 / Chapter A.1 --- Proof of Static Optimal Peering Strategy --- p.61 / Chapter A.2 --- Proof of Strategy for Peering over T Time Slot --- p.65 / Chapter A.3 --- Proof of Strategy for Peering over One Time Slot --- p.66