As the Internet grows, there are several problems needed be solve. First, the IP addresses will be exhausted. The 128 bits IPv6 addresses will replace the 32 bits IPv4 addresses to solve the problem. Secondly, routers become the bottlenecks of networks. There are many routing lookup algorithms to improve routers' performance. In July 1998, the detail address formats of IPv6 are defined by the IETF in RFC 2373, 2374 and 2375. These definitions make the discussion of routing lookup algorithms from IPv4 to IPv6 become possible. This paper focuses on the scalability of performing those IPv4 routing lookup algorithms for IPv6. The paper also proposals a new IPv6 lookup algorithm based on the characteristics of the IPv6 address formats. Chapter 1 is introduction. Chapter 2 introduces the current IPv6 addressing types and reviews previous work on IPv4. Chapter 3 presents our modified IPv6 routing lookup algorithm. Chapter 4 describes the generation of the test patterns for IPv6 lookups and presents the simulation results. Chapter 5 concludes this paper.

Abstract In large-scale distributed multiprocessor systems, communication delay becomes the bottleneck of system performance. A main factor which affects communication delay is the adopted routing method and the router design light traffic, the queuing delay can be increased drastically due to message congestion. We have developed a hierarchical globally adaptive routing method. The method can poll global traffic status. According to the traffic status, it can select a routing path congestion which can alleviate. Therefore, the queuing delay due to congestion can be reduces significantly non-light traffic globally. We also developed two detail routing methods applied at different hierarchical routing levels¡Gthe look around routing method and the parallel approximate maze routing method. They can avoid selecting a routing path via congested regions as much as possible. In this research, we designed a performance simulator of the globally adaptive mesh router. We also provided a traffic with the different levels of non-uniform traffic distribution. We utilized the performance simulator to exercise minimal routing, adaptive routing and our globally adaptive routing methods. The experiment results show that our globally adaptive method obtains significant performance improvement in non-light traffic.

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A three parameter pseudo-linear reservoir model was developed and tested using data collected from urban catchments in Nottingham. Some 550 individual rainfall-runoff events, from ten different catchments, were recorded (from May 1983 to June 1985) and available for analysis. parameters, depression storage and runoff an effective hyetograph to be obtained from the The third parameter, KATCH, was a catchment obtained by an optimisation technique applied to Two- of the model coefficient, enabled measured hyetograph. constant which was development data sets. The rainfall loss parameters were determined using both the traditional method of linear regression analysis of rainfall-runoff depths, and by model optimisation of development data sets. Two versions of the pseudo-linear reservoir model were tested and results from both versions were compared with the results from the non-linear reservoir model, which is the overland flow routing model currently used in the Wallingford Procedure for the design and analysis of urban storm drainage in the United Kingdom. When the overall goodness-of-fit between simulated and observed hydrographs was assessed (using the Biassed Integral Square Error, BISE), similar model performance results were obtained for both versions of the pseudo-linear reservoir model and the non-linear reservoir model applied to paved surfaces. The pseudo-linear reservoir model accounted for the routing of flows, both on the surface and through the secondary drainage system, via the catchment constant, KATCH. For the two sub-catchments with secondary drains, the non-linear reservoir model over-estimated peak flows by some 401, since the model ignores routing through the drains. The pseudo-linear reservoir model gave consistently better results when compared with the non-linear reservoir model for storms monitored from an uncalibrated sub-catchment of mixed roof and paved surfaces. (

Network Routing problems focus on exploiting the network-based struc- ture of a mathematical optimization problem to establish e cient solutions that are tailored to the problem at hand. The topic of this dissertation relates to a speci c class of network routing problems, those in which the properties of the nodes and/or links in the network can be represented as instances of a particular network-state realization, where the set possible network-state can be represented by a discrete probability distribution. The main contribution of this research is to formalize the de nition of such families of network-states, a construct we de ne as Stochastic-State Networks (SSN), and show that certain properties of such networks can allow for the systematic development of exact and heuristic solution procedures for a speciric class of network routing problems. The class of network problems considered are those in which dynamic routing decisions are seeked, and where information about the network can only be gathered through direct observation of the instantiation of the stochastic elements of the network. Two speci c instances of routing problems are considered: a dynamic instance of a Traveling Salesman Problem, and a routing problem in the presence of stochastic link failures. Exact methods and heuristics are developed by exploiting the underlaying stochastic-state network formulation and numerical results are presented. / text

The purpose of this master thesis is to reduce the transportation costs and environmental distress by improving the transportation routes needed to supply the sawmills in the county of V¨asterbotten, Sweden, their raw material. It is of particular interest to explore the possible benefits of implementing a so called virtual transshipment hub for this purpose. The outline of the hub is to allow the companies within the system to deduce raw materials from other companies’ contracted harvesting areas. The hub would thus create a pool of the total raw material appointed by each specific company. These companies may deduce the raw material needed but can have it transported from a closer site than their own contracted lumbering area. Sawmill companies rely on the use of harvesting areas to provide the needed raw material and it is of common practice to contract different harvest areas. The thesis is that the permission to use other companies’ harvest areas would create new possible routes resulting in better planning and as an extension more efficient routes. This master thesis will investigate the current situation in the industry and adapt a model suitable for the purpose from the information gathered. This thesis work will also provide a number of cost allocation models which are used in cooperations between different companies in order to determine how to allocate the savings / costs between the companies. It was revealed in an interview that it was desired to include an exploration of the ETT trucks in this paper. The ETT trucks is a new type of truck which is not currently permitted in Sweden. It has a higher loading capacity than the conventional trucks used today. Gathering data proved much more difficult than initially anticipated. As a result, this paper will not provide any actual data testing, but the Results section will show that the model is working as intended by using with trivial data. More on the difficulties associated with the data in the section Discussion. Due to the trivial data it is impossible to express an actual cost saving in using a numerical value or percentage. The results from this survey did however show that there were a signification reduction of the cost associated with the transportation of raw material when the two companies tested cooperated in comparison to when they worked separately. The use of the ETT trucks would reduce the transportation costs and CO2 emissions by 20 % respectively, as presented in a survey conducted by L¨ofroth and Svenson (2012). The conclusion is that regardless if the government allows the use of ETT trucks, it should lie in the best interest to further explore the implementation of a virtual transshipment hub using real data and a thorough investigation of eligible participants through the cost allocation models and a subsequent maintenence of the system using supply chain management.

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The Internet consists of over 50 thousand smaller networks, called Autonomous Systems (ASes) (e.g., AT&T, Sprint, Google), that use the Border Gateway Protocol (BGP) to figure out how to reach each other. One way or another, we all rely on BGP because it is what glues the Internet together, but despite its crucial role, BGP remains vulnerable to propagation of bogus routing information due to malicious attacks or unintentional misconfigurations. The United States Department of Homeland Security (DHS) views BGP security as part of its national strategy for securing the Internet, and there is a big push to standardize a secure variant of BGP (S*BGP) by the Internet Engineering Task Force (IETF). However, S*BGP properties and their impact on the Internet's routing infrastructure, especially in partial deployment, have not yet been fully understood. To address this issue, in this thesis we use methodologies from applied cryptography, algorithms, and large scale simulations to study the following three key properties with respect to their deployment: 1. provable security guarantees, 2. stability in full and partial deployment with or without attackers, 3. benefits and harm resulting from full and partial deployment. With our analysis we have discovered possible security weaknesses in previously proposed secure BGP variants and suggest possible fixes to address them. Our analysis also reveals that security benefits from partially deployed S*BGP are likely to be meager, unless a significant fraction of ASes deploy it. At the same time, complex interactions between S*BGP and the insecure, legacy BGP can introduce new vulnerabilities and instabilities into the Internet's routing infrastructure. We suggest possible strategies for mitigating such pitfalls and facilitating S*BGP deployment in practice.

In this thesis, an investigation of the performance of multipath routing in Wireless Sensor Networks (WSN) is performed. The communication in the network under study is to take place from individual nodes to the sink node. The investigation involved multipath finding methods in WSN. Also, it involves investigating the weight assignment, traffic splitting and route selection methods for the different paths discovered by each node in the WSN. Also, a comparison between Hybrid Routing Protocol, Source Routing Protocol and Diffusion Routing Protocol is performed. A simple traffic routing algorithm for each routing protocol has been developed to conceptualize how the network traffic is routed on a set of active paths. The investigation of the Hybrid, Source and Diffusion Routing Protocol involved using multiple paths simultaneously to transmit messages that belong to the same flow by using a weight assigned to each path and transmit each message as a whole. Finally, the power consumption and the QoS in terms of message delays for a WSN were investigated and compared between different protocols.

A mobile social network (MSN) is defined as a mobile network that uses social relationships to allow its nodes to communicate. Many wireless networks including ad hoc networks do not reflect a real world deployment because of routing implementation difficulties. However, with the enormous use of social network sites (SNSs) including Twitter and Facebook, MSNs are expected to make the implementation of routing easier. Thus, some research activity has been devoted to routing protocols in such networks. This task is very challenging, thus only a few MSN routing protocols have been proposed in the literature. However, these protocols suffer from either a low delivery ratio or high memory requirements. This thesis presents a new routing protocol (Status) for MSNs which has excellent performance in terms of delivery ratio and memory requirements. Status takes advantage of the online status of a node to make forwarding decisions. Status has a low overhead ratio, low average delay and low computational complexity at the node level. All of these features are examined in this thesis. Simulation results are presented which show that Status outperforms other routing protocols such as Epidemic and PRoPHET with a realistic mobility model, namely, the shortest path movement based model (SPMBM). Status does not have high memory requirements since it does not store the online status of other nodes. Instead, an instance check is done when two nodes meet. Since messages are forwarded without probability calculations based on contact history, Status also has low computational complexity. / Graduate