The Internet faces well-known challenges in realizing modifications to the core architecture. To help overcome these limitations, the use of network virtualization has been proposed. Network virtualization enables the deployment of novel network architectures and services on existing Internet infrastructure. Virtual networks run over physical networks and use Internet paths and protocols as essentially a link layer in the virtual network. Virtual networks can also share the resources in the physical substrate. Effective use of the underlying substrate network requires intelligent placement of virtual networks so that underlying resources do not incur over-subscription. Because virtual networks can come and go over time, and underlying networks can experience their own dynamic changes, virtual networks need to be migrated---re-mapped to the physical network during active operation---to maintain good performance. While virtual network placement, and to a lesser extent migration, has been studied in the past, little attention has been devoted to designing, deploying, and evaluating migration mechanisms for virtual networks. In this dissertation, we design virtual network migration mechanisms for different substrate platforms and further design a system to mitigate the effects of virtual network migration. In particular this dissertation makes the following contributions: 1. With the goal of minimizing the disruption during a virtual network migration, we design three algorithms for scheduling the sequence of virtual router moves that takes a virtual network from its original placement to its new placement. 2. We design and implement a controller-based architecture for virtual network migration on PlanetLab. This work explores the challenges in implementing virtual network migration on real infrastructure. Recommendations are given for infrastructure that support virtual network migration. 3. We propose and implement a mechanism to mitigate the performance degradation resulting from virtual network migration through transport and application layer collaboration. We utilize a centralized controller to notify the end-systems or the gateways about the time of the virtual network migration such that we prevent packet loss to the application traffic of the end-systems.

Embedding of virtual network (VN) requests on top of a shared physical network poses an intriguing combination of theoretical and practical challenges. Two major problems with the state-of-the-art VN embedding algorithms are their indifference to the underlying substrate topology and their lack of re-optimization mechanisms for already embedded VN requests. We argue that topology-aware embedding together with re-optimization mechanisms can improve the performance of the previous VN embedding algorithms in terms of acceptance ratio and load balancing. The major contributions of this thesis are twofold: (1) we present a mechanism to differentiate among resources based on their importance in the substrate topology, and (2) we propose a set of algorithms for re-optimizing and re-embedding initially-rejected VN requests after fixing their bottleneck requirements. Through extensive simulations, we show that not only our techniques improve the acceptance ratio, but they also provide the added benefit of balancing load better than previous proposals. The metrics we use to validate our techniques are improvement in acceptance ratio, revenue-cost ratio, incurred cost, and distribution of utilization.

Embedding of virtual network (VN) requests on top of a shared physical network poses an intriguing combination of theoretical and practical challenges. Two major problems with the state-of-the-art VN embedding algorithms are their indifference to the underlying substrate topology and their lack of re-optimization mechanisms for already embedded VN requests. We argue that topology-aware embedding together with re-optimization mechanisms can improve the performance of the previous VN embedding algorithms in terms of acceptance ratio and load balancing. The major contributions of this thesis are twofold: (1) we present a mechanism to differentiate among resources based on their importance in the substrate topology, and (2) we propose a set of algorithms for re-optimizing and re-embedding initially-rejected VN requests after fixing their bottleneck requirements. Through extensive simulations, we show that not only our techniques improve the acceptance ratio, but they also provide the added benefit of balancing load better than previous proposals. The metrics we use to validate our techniques are improvement in acceptance ratio, revenue-cost ratio, incurred cost, and distribution of utilization.

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Network virtualization can offer more flexibility and better manageability for the future Internet by allowing multiple heterogeneous virtual networks (VN) to coexist on a shared infrastructure provider (InP) network. A major challenge in this respect is the VN embedding problem that deals with the efficient mapping of virtual resources on InP network resources. Previous research focused on heuristic algorithms for the VN embedding problem assuming that the InP network remains operational at all times. In this thesis, we remove that assumption by formulating the survivable virtual network embedding (SVNE) problem and developing baseline policy heuristics and an efficient hybrid policy heuristic to solve it. The hybrid policy is based on a fast re-routing strategy and utilizes a pre-reserved quota for backup on each physical link. Our evaluation results show that our proposed heuristic for SVNE outperforms baseline heuristics in terms of long term business profit for the InP, acceptance ratio, bandwidth efficiency, and response time.

Abstract Mobile phone is one essential communication product to most Taiwanese nowadays. As the market approaching its full capacity, service providers are now facing more competitions than ever. Some much lower profit and decreasing number of users can also be expected. Hence all the telecommunication service providers are trying to increase their revenue through providing mobile digital services to compensate the decreasing revenue from voice sector. To be more precisely, telecommunication service providers are not solely telecomm operators after the integration with mobile data transfer. Mobile phone system is also changing from telecommunication system to a multifunctional mobile communication system. 3G (The 3rd Generation Mobile System) is the solution that meets new mobile communication requirements. The system is based in a new technology of wireless communication with a very high speed access to the Internet services. Mobility is the basic requirement of mobile networking service, the 3G system is enhancing the capability of mobile communication that allows us accessing the Internet, enjoying the multimedia entertainment, inquiring information, and doing mobile business anywhere. 3G is also giving the mobility to modern business activities. For instance, users can now accessing data, sharing interactive application software, and attending video conference through Internet and Intranet services. While users can now performing all these activities in anytime and place, the service boundaries between telecommunication, information, media, and entertainment will disappear. All these services will now be integrated, current fixed services will soon turn into mobile. We can watch video clips and receiving emails in the same time, also play on-line games with friends in any different corner around the world. From 9.6Kbps to 2Mbps, the data transmission speed of 3G system is 40 times faster than GSM system. It may now take 2 minutes to send a multimedia message with a photo and voice attachment, but in the future 3G system, it will be done within 5 minutes. Nonetheless, the 3G system is not only providing high speed data transfer services, but also the convenience of accessing data. The core technology of 3G is packed Internet Protocol which allows users to get wired anytime. Emails can easily be downloaded to the mobile phone handset too. Just press one button, employees can easily get connected with their company. Service providers will charge only when the users are retrieving data from the Internet, otherwise all services are free. The application of wireless services will be extended in the future. The needs of interaction between consumers and mobile equipment, also between one equipment and another will continue increasing. These interactions include system failure noticing, new order placing, or data transmitting. In addition to the telecommunication operators, businesses can also take good advantages of 3G to develop new applications. 3G will be a part of our life in the future. The licenses of 3G operators have already been issued in February 2002. How firms can develop one successful business model of mobile strategy has already become the critical issue for these operators. This research is focusing on the reactions of telecommunication market after the introduction of 3G services. The research topics include exploring the technical problems of 3G system, analyzing the impact of current GPRS, i-mode, MMS, WLAN, PHS to the 3G system, also examining the attitudes of different governments in launching the 3G system in the global market. A conclusion remark will be made with the analysis of current operations of services providers and the future trend of the market.

Network virtualization can offer more flexibility and better manageability for the future Internet by allowing multiple heterogeneous virtual networks (VN) to coexist on a shared infrastructure provider (InP) network. A major challenge in this respect is the VN embedding problem that deals with the efficient mapping of virtual resources on InP network resources. Previous research focused on heuristic algorithms for the VN embedding problem assuming that the InP network remains operational at all times. In this thesis, we remove that assumption by formulating the survivable virtual network embedding (SVNE) problem and developing baseline policy heuristics and an efficient hybrid policy heuristic to solve it. The hybrid policy is based on a fast re-routing strategy and utilizes a pre-reserved quota for backup on each physical link. Our evaluation results show that our proposed heuristic for SVNE outperforms baseline heuristics in terms of long term business profit for the InP, acceptance ratio, bandwidth efficiency, and response time.

Network function virtualization (NFV) and software-dened networking (SDN) are two recent networking paradigms that strive to increase manageability, scalability, pro- grammability and dynamism. The former decouples network functions and hosting devices, while the latter decouples the data and control planes. As more and more service providers adopt these new paradigms, there is a growing need to address multi-failure conditions, particularly those arising from large-scale disaster events. Overall, addressing the virtual network function (VNF) placement and routing problem is crucial to deploy NFV surviv- ability. In particular, many studies have inspected non-survivable VNF provisioning, however no known work have proposed survivable/resilient solutions for multi-failure scenarios. In light of the above, this work proposes and deploys a survivable multi-objective provisioning solution for NFV infrastructures. Overall, this study initially proposes multi- objective solutions to eciently solve the VNF mapping/placement and routing problem. In particular, a integer linear programming (ILP) optimization and a greedy heuristic meth- ods try to maximize the requests acceptance rate while minimizing costs and implementing trac engineering (TE) load-balancing. Next, these schemes are expanded to perform \risk- aware" virtual function mapping and trac routing in order to improve the reliability of user services. Furthermore, additionally to the ILP optimization and greedy heuristic schemes, a metaheuristic genetic algorithm (GA) is also introduced, which is more suitable for large- scale networks. Overall, these solutions are then tested in idealistic and realistic stressor scenarios in order to evaluate their performance, accuracy and reliability.

This thesis will address a problem concerning availability of information systems at an enterprise within the financial sector and its external suppliers, so called trusted third party. The information system resides on the internal network of the enterprise and must be available to both employees of the enterprise and the trusted third party simultaneously. This contradicts the company policy which disallows third parties access to the internal network. The HAVECA-model introduced in this thesis provides a framework of methods, each solving a sub problem identified in the model. The identified methods are hardening, verification, control and assurance, together supplying a method for continuously securing the internal network against a trusted third party. The HAVECA-model will be applied to a scenario, providing real-world examples of techniques of allowing the trusted third party to a restricted number of servers on the network. / Robert Karlsson e-mail: robert@iron.se Aron Rydquist e-mail: aaron@linux.se

Deploying virtual network functions (VNFs) such as WAN accelerators, network address translators (NATs) and 5G functions at the network edge (NE) can significantly reduce the experienced latency of delay-ultrasensitive applications (e.g., autonomous vehicles and Internet of things). Nonetheless, a major challenge to their anticipated large-scale deployment is the ability to efficiently allocate and manage the scarce NE resources hosting these functions. In this thesis, we describe a novel containerized infrastructure manager (cIM) that extends current managers, such as Kubernetes, with the necessary building blocks to provide an accurate yet elastic resource allocation service to containerized VNFs at scale. The proposed cIM treats the main modules of the VNFs, i.e., the containerized VNF components (cNFCs), as atomic special-purpose functions that can be rapidly deployed to form complex network services. The main component of the proposed cIM, the resource reservation manager (RRM), employs concepts of risk pooling in the insurance industry to accurately reserve the needed resources for the hosting containers. More precisely, to meet anticipated cNFCs demand fluctuation, the RRM accurately reserves a quota of additional resources that are shared by the containerized functions collected together in clusters. The reserved quota of resources ensures the desired availability level of the cNFCs without over-provisioning the scarce resources of the NE. The RRM considers three different situations namely that of a cNFC instance, a cluster of cNFCs or multiple cNFC clusters sharing the reserved resources. Different allocation approaches are then presented for each of these three situations. Simulation experiments are conducted to evaluate the performance of our reservation schemes from different aspects. The corresponding experimental results demonstrate that our proposed cIM can significantly improve the performance of the cNFCs and guarantee their desired availability with minimal resource reservation. Optimal allocation solutions of the resource pools are further proposed considering the desired availability level and the limit of resource pools. The evaluation results demonstrate that our optimization models and solutions obtain the best performance of relevant testing parameters, e.g., availability.