Thesis (M.S.)--University of South Florida, 2003. / Title from PDF of title page. Document formatted into pages; contains 62 pages. Includes bibliographical references.

This thesis presents several decentralized, learning-based algorithms for on-line routing of bandwidth guaranteed paths. The presented routing algorithms do not need any a-priori knowledge of traffic demand; they use only their locally observed events and update their routing policy using learning schemes. The employed learning algorithms are either learning automata or the multi-armed bandit algorithms. We investigate the asymptotic behavior of the proposed routing algorithms and prove the convergence of one of them to the user equilibrium. Discrete event simulation results show the merit of these algorithms in terms of improving the resource utilization and increasing the network admissibility compared with shortest path routing. / We investigate the performance degradation due to decentralized routing as opposed to centralized optimal routing policies in practical scenarios. The system optimal and the Nash bargaining solutions are two centralized benchmarks used in this study. We provide nonlinear programming formulations of these problems along with a distributed recursive approach to compute the solutions. An on-line partially-decentralized control architecture is also proposed to achieve the system optimal and the Nash bargaining solution performances. Numerical results in some practical scenarios with well engineered networks, where the network resources and traffic demand are well matched, indicate that decentralized learning techniques provide efficient, stable and scalable approaches for routing the bandwidth guaranteed paths. / In the context of on-line learning, we propose a new algorithm to track the best action-selection policy when it abruptly changes over time. The proposed algorithm employs change detection mechanisms to detect the sudden changes and restarts the learning process on the detection of an abrupt change. The performance analysis of this study reveals that when all the changes are detectable by the change detection mechanism, the proposed tracking the best action-selection policy algorithm is rate optimal. On-line routing of bandwidth guaranteed paths with the potential occurrence of network shocks such as significant changes in the traffic demand is one of the applications of the devised algorithm. Simulation results show the merit of the proposed algorithm in tracking the optimal routing policy when it abruptly changes.

As Multi-Protocol Label Switched (MPLS) networks increase in usage and size, the number of traffic engineered tunnels or Label Switched Paths (LSPs) which must be established has an impact on network state maintenance, administration and scalability. The ability to signal and meet Quality-of-Service (QoS) requirements in such networks has been addressed through the addition of Differentiated Services (Diff-Serv) mappings and other traffic engineering mechanisms. However, for the purpose of path computation, route advertisements, signaling and admission control, multiple traffic classes carried together are still treated as a single class. This work explores extensions to MPLS which allow for the accommodation of up to eight distinct traffic classes per label switched path. Through an examination of simulation results. a comparison between existing methods and the proposed additions is made that shows scenarios in which such traffic class aggregation or "bundling" provides a significant reduction in the number of paths which must be maintained in the network.

REROUTE SEQUENCE PLANNING IN MULTIPROTOCOL LABEL SWITCHING NETWORKS &Ouml / zbilgin, izzet G&ouml / khan M.S., Department of Electrical and Electronics Engineering Supervisor: Asst. Prof. Dr. C&uuml / neyt F. Bazlama&ccedil / ci December 2004, 57 pages The growth of the Internet has caused the development of new protocols that enable IP networks to be engineered efficiently. One such protocol, Multiprotocol Label Switching (MPLS) enables IP datagrams in backbone networks to be forwarded based on the label switching forwarding paradigm. In MPLS networks, rerouting of Label Switching Paths (LSPs) can be needed in order to attain a better resource utilization in the network. In this case, a sequence of LSPs has to be found for their one by one reconfiguration without service interruption, involving the constraint that the link capacities should not be violated at any time during the rerouting process. This reroute sequence planning problem for LSPs is NP-complete. In previous works, the conditions of existence of any feasible reroute sequence are examined and algorithms are described for solving the problem, but it was shown that the problem is computationally hard in real-world situations because of the large amount of routers and LSPs in the network. In this work, we deal with the problem of reroute sequence planning problem of LSPs and present alternative solutions for the case when there is no feasible solution. We introduce a tool for the post-processing phase when a capacity violation is occurred during the sequence planning. We present an algorithm trying to reconfigure LSPs while allowing some interruption or degradation of traffic during the rerouting process.

Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 122-126). Also available in electronic format on the Internet.

Thesis (M. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 96-101). Also available in electronic format on the Internet.

Thesis (MSc)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (M.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 90-94). Also available in electronic format on the Internet.

Dissertação (mestrado) - Pontifícia Universidade Católica do Paraná, Curitiba, 2008 / Bibliografia: f. 60-64 / Este trabalho apresenta um método de otimização off-line para determinação de LSPs (Label Switched Paths) próxima ao ótimo para redes MPLS com suporte a proteção de caminho. O objetivo deste método é determinar caminhos principais e de recuperação para mú / This work presents an off-line optimization approach for determining near-optimal LSPs (label Switched Paths) for MPLS-based networks with support to path-protection. The objective of the method proposed in this paper is to determine working and recovery

Over the last years, we have witnessed a rapid deployment of real-time applications on the Internet as well as many research works about Quality of Service (QoS) in particularly IPv4 (Internet Protocol version 4). The inevitable exhaustion of the remaining IPv4 address pool has become progressively evident. As the evolution of Internet Protocol (IP) continues, the deployment of IPv6 QoS is underway. Today, there is limited experience in the deployment of QoS for IPv6 traffic in MPLS backbone networks in conjunction with DiffServ (Differentiated Services) support. DiffServ itself does not have the ability to control the traffic which has been taken for end-to-end path while a number of links of the path are congested. In contrast, MPLS Traffic Engineering (TE) is accomplished to control the traffic and can set up end-to-end routing path before data has been forwarded. From the evolution of IPv4 QoS solutions, we know that the integration of DiffServ and MPLS TE satisfies the guaranteed QoS requirement for real-time applications. This thesis presents a QoS performance study of real-time applications such as voice and video conferencing over DiffServ with or without MPLS TE in IPv4/IPv6 networks using Optimized Network Engineering Tool (OPNET). This thesis also studies the interaction of Expedited Forwarding (EF), Assured Forwarding (AF) traffic aggregation, link congestion, as well as the effect of various performance metrics such as packet end-to-end delay, packet delay variation, queuing delay, throughput and packet loss. The effectiveness of DiffServ and MPLS TE integration in IPv4/IPv6 network is illustrated and analyzed. The thesis shows that IPv6 experiences more delay and loss performance than their IPv4 counterparts. / Author (1): Md. Tariq Aziz Address: C/O: Murshed Gularm, Nykarleby Gatan 134, 16474 Kista, Stockholm, Sweden Author (2): Mohammad Saiful Islam Address: Minnervavägen 22B, 371 43 Karlskrona, Sweden