MPLS is a widely used technology in the service providers and enterprise networks across the globe. MPLS-enabled infrastructure has the ability to transport any type of payload (ATM, Frame Relay and Ethernet) over it, subsequently providing a multipurpose architecture. An incoming packet is classified only once as it enters into the MPLS domain and gets assigned label information; thereafter all decision processes along a specified path is based upon the attached label rather than destination IP addresses. As network applications are becoming mission critical, the requirements for fault tolerant networks are increasing, as a basic requirement for carrying sensitive traffic. Fault tolerance mechanisms as provided by an IP/MPLS network helps in providing end to end “Quality of Service” within a domain, by better handling blackouts and brownouts. This thesis work reflects how MPLS increases the capability of deployed IP infrastructure to transport traffic in-between end devices with unexpected failures in place. It also focuses on how MPLS converts a packet switched network into a circuit switched network, while retaining the characteristics of packet switched technology. A new mechanism for MPLS fault tolerance is proposed.

Diseño orientado al desarrollo de una plataforma de comunicaciones utilizando redes inálambricas de datos y software libre. La prioridad en las comunicaciones esta desarrollada en diferentes tipos de tecnología para poder satisfacer este mercado creciente. Se mostrará como con la tecnología propuesta, se puede obtener calidad y prioridad de la voz en las redes tanto ethernet como también en wireless.

In the twenty century multimedia entertainment is more and more proportion in the human life and internet is more covenient to communicate and easier to change information. Video and audio compression technology are promote rapidly to drive people enjoying multimedia contents by using internet. However, the main three software factory provide high price of multimedia streaming technology and they have each patents on their multimedia streaming technology. From MP3 encoding technology view, it is used efficient to compress music data and let it be in trade of data size and high quality. MP3 file format is much appropriate to apply using many kinds based on streaming music applications. The technique in my paper, first I analysis MP3 encoding and deconding algorithm. Then I apply it in transferring streaming music by using reliable TCP/IP communication protocol to make multi-user and multi-channel music-on-demand system. By using Java server side technology, I make a web-based manager and user interface system and finally make the implementation of linux-based MP3 music-on-demand system.

The Denial-of-Service (DoS) attacks with the source IP address spoofing techniques has become a major threat to the Internet. An intrusion detection system is often used to detect DoS attacks and to coordinate with the firewall to block them. However, DoS attack packets consume and may exhaust all the resources, causing degrading network performance or, even worse, network breakdown. A proactive approach to DoS attacks is allocating the original attack host(s) issuing the attacks and stopping the malicious traffic, instead of wasting resources on the attack traffic. In this research, an ant-based traceback approach is proposed to identify the DoS attack origin. Instead of creating a new type or function needed by the router or proceeding the high volume, find-grained data, the proposed traceback approach uses flow level information to spot the origin of a DoS attack. Two characteristics of ant algorithm, quick convergence and heuristic, are adopted in the proposed approach on finding the DoS attack path. Quick convergence efficiently finds out the origin of a DoS attack; heuristic gives the solution even though partial flow information is provided by the network. The proposed method is validated and evaluated through the preliminary experiments and simulations generating various network environments by network simulator, NS-2. The simulation results show that the proposed method can successfully and efficiently find the DoS attack path in various simulated network environments, with full and partial flow information provided by the network.

In mobile IP, a triangular routing problem usually leads to additional delays and non-seamless handoff, which causes the loss of a large amount of in-fly packets. In this thesis we propose an adaptive route optimization scheme that considers the seamless handoff and mobility rate. The proposed scheme adopts the mobile routing table scheme and includes an efficient cost function. The cost function is a trade-off between network bandwidth utilized by the routing path, signaling messages and processing loads of agents. The primary idea is to adaptively determine when to perform route optimization. The effect of the mobility rate and the cell sojourn time of a mobile node are studied. Both new call and handoff call are considered in the cost calculation. Simulation result shows that the proposed scheme can effectively reduce the total cost composed of link and signaling costs.

With the flourishing development of the Internet and progress of science and technology, the wireless network technology is growing up rapidly at present. People can make connections through the Internet whenever and wherever possible. Mobile IPv6 is proposed in order to support mobility in IPv6 network, offers safer and more efficient mobile communication service to users than Mobile IPv4. However, it still suffers long delays and high packet losses. In order to enable smooth handovers, many researches in which use buffering and forwarding methods have been proposed. Although these proposals significantly improve handover performances, they suffer from the out-of-order delivery problem. This paper proposes a scheme which integrates multicast technologies with FMIPv6 for improving the handover performance. By switching between unicast addressing mode and multicast addressing mode, and letting the access router of the new network (NAR) join the multicast group in anticipation during handover, correspondent nodes (CNs) can transmit data packets to the new and old networks of mobile nodes (MNs) directly at the same time. It not only averts the out-of-order delivery problem, but also reduces the effect of the Duplicated Address Detection (DAD) time on the service disruption time.

The technique of direct-sequence (DS) code division multiple access (CDMA) cellular systems has been the focus of increased attention. In this thesis, the problem of narrow-band interference (NBI) cancellation for the DS-CDMA communication systems is considered. It has been shown that the performance of single NBI cancellation for CDMA systems by using the non-linear filtering approach, the so-called DDK filter or the MDK filter, is superior to the one using the linear filtering approach. The main concern of this thesis is to deal with the multiple NBI cancellation. This may occur in some practical application, for instance, in the 2.4GHz CDMA system, the bluetooth and wireless LAN may exist in the same frequency band with different power ratio. In this thesis, the nonlinear filtering with fast convergence least square (LS) algorithms, viz., the modified inverse QRD-RLS (IQRD-RLS) and the interior point (IP) LS algorithms, are devised for multiple NBI cancellation in the multi-user CDMA system. In fact, the IQRD-RLS and the IP LS algorithms are known to have better numerical stability and convergence property in the RLS family. Since in the non-linear MDK filter with the IQRD-RLS algorithm, the prediction error £`k,k-1 used in the conventional IQRD-RLS is replaced by the nonlinear function of £l(£`k,k-1), and is defined to as the modified IQRD-RLS algorithm. The merits of the proposed algorithms are verified via computer simulation. We showed that the performance of our proposed algorithms outperformed the one using the conventional nonlinear filtering approach with LMS algorithm, in terms of convergence property and the signal-to-noise ratio improvement (SNRI).

The purpose of this article is to identify how Internet Protocol Virtual Private Network (IP VPN) affects the business strategy for Taiwan Internet Service Provider, using X Company as an example. With the change in technology, the world¡¦s business environment change from day to day. The break though development such as Internet Protocol Virtual Private Network, create a whole new era of communication. With the pressure coming from both the fixed network carrier (Type 1 telecommunications enterprises) and the existing Internet service provider competitors. X Company needs to find a new market niche to maintain its competition. Strategy becomes most important when the existing business model is coming into a mature stage. A partnership with other service carriers or an innovation within the same business filed becomes the crucial decision. Through X Company¡¦s internal data, this thesis will analyzed the strength and weakness compare to its current competitors. With the data from the customer survey, X Company can also identify the need of its customers. At the end, this thesis will prove X Company¡¦s trend toward IP VPN transformations is the right strategy. As data traffic expected to outgrow voice traffic in the coming year, X Company¡¦s transformation to IP-based Virtual Private Networks is the right strategy. IP VPN setup will be the trend of increasing dependence on the corporate network as a way of interconnecting users with enterprise software, business process, databases, and intellectual capital. Companies are transferring more enterprise applications between sites, as well as data replication and transfer. But enterprises are aiming at the same time to combine the effectiveness of information sharing with the network with the need to make sure security, manageability, functionality and privacy while being paying attention on cost control. X Company IP VPNs offer a more reasonable mean of doing so without the necessity for expensive leased line dedicated connections.

The IP lookup in internet routers requires implementation of the longest prefix match algorithm. The software or hardware implementations of routing trie based approaches require several memory accesses in order to perform a single memory lookup, which limits the throughput considerably. On the other hand, IP lookup throughput requirements have been continuously increasing. This has led to ternary content addressable memory(TCAM) based IP lookup engines which can perform a single lookup every cycle. TCAM lookup engines are very power hungry due to the large number of entries which need to be simultaneously searched. This has led to two disparate streams of research into power reduction techniques. The first research stream focuses on the routing table compaction using logic minimization techniques. The second stream focuses on routing table partitioning. This work proposes to bridge the gap by employing strategies to combine these two leading state of the art schemes. The existing partitioning algorithms are generally employed on a binary routing trie precluding their application to a compacted routing table. The proposed scheme employs a ternary routing trie to facilitate the representation of the minimized routing table in combination with the ternary trie partitioning algorithm. The combined scheme offers up to 50% reduction in silicon area while maintaining the power economy of the partitioning scheme.

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨ Der Vortrag gibt einen Überblick über den aktuellen Stand (April 2000) von IP-Multicast im Campusnetz und die MBONE-Anbindung der TU Chemnitz.