User-Centric Quality of Service Provisioning in IP Networks

The Internet has become the preferred transport medium for almost every type of communication, continuing to grow, both in terms of the number of users and delivered services. Efforts have been made to ensure that time sensitive applications receive sufficient resources and subsequently receive an acceptable Quality of Service (QoS). However, typical Internet users no longer use a single service at a given point in time, as they are instead engaged in a multimedia-rich experience, comprising of many different concurrent services. Given the scalability problems raised by the diversity of the users and traffic, in conjunction with their increasing expectations, the task of QoS provisioning can no longer be approached from the perspective of providing priority to specific traffic types over coexisting services; either through explicit resource reservation, or traffic classification using static policies, as is the case with the current approach to QoS provisioning, Differentiated Services (Diffserv). This current use of static resource allocation and traffic shaping methods reveals a distinct lack of synergy between current QoS practices and user activities, thus highlighting a need for a QoS solution reflecting the user services. The aim of this thesis is to investigate and propose a novel QoS architecture, which considers the activities of the user and manages resources from a user-centric perspective. The research begins with a comprehensive examination of existing QoS technologies and mechanisms, arguing that current QoS practises are too static in their configuration and typically give priority to specific individual services rather than considering the user experience. The analysis also reveals the potential threat that unresponsive application traffic presents to coexisting Internet services and QoS efforts, and introduces the requirement for a balance between application QoS and fairness. This thesis proposes a novel architecture, the Congestion Aware Packet Scheduler (CAPS), which manages and controls traffic at the point of service aggregation, in order to optimise the overall QoS of the user experience. The CAPS architecture, in contrast to traditional QoS alternatives, places no predetermined precedence on a specific traffic; instead, it adapts QoS policies to each individual’s Internet traffic profile and dynamically controls the ratio of user services to maintain an optimised QoS experience. The rationale behind this approach was to enable a QoS optimised experience to each Internet user and not just those using preferred services. Furthermore, unresponsive bandwidth intensive applications, such as Peer-to-Peer, are managed fairly while minimising their impact on coexisting services. The CAPS architecture has been validated through extensive simulations with the topologies used replicating the complexity and scale of real-network ISP infrastructures. The results show that for a number of different user-traffic profiles, the proposed approach achieves an improved aggregate QoS for each user when compared with Best effort Internet, Traditional Diffserv and Weighted-RED configurations. Furthermore, the results demonstrate that the proposed architecture not only provides an optimised QoS to the user, irrespective of their traffic profile, but through the avoidance of static resource allocation, can adapt with the Internet user as their use of services change.France Teleco

Scalable Multiple Description Coding and Distributed Video Streaming over 3G Mobile Networks

In this thesis, a novel Scalable Multiple Description Coding (SMDC) framework is proposed. To address the bandwidth fluctuation, packet loss and heterogeneity problems in the wireless networks and further enhance the error resilience tools in Moving Pictures Experts Group 4 (MPEG-4), the joint design of layered coding (LC) and multiple description coding (MDC) is explored. It leverages a proposed distributed multimedia delivery mobile network (D-MDMN) to provide path diversity to combat streaming video outage due to handoff in Universal Mobile Telecommunications System (UMTS). The corresponding intra-RAN (Radio Access Network) handoff and inter-RAN handoff procedures in D-MDMN are studied in details, which employ the principle of video stream re-establishing to replace the principle of data forwarding in UMTS. Furthermore, a new IP (Internet Protocol) Differentiated Services (DiffServ) video marking algorithm is proposed to support the unequal error protection (UEP) of LC components of SMDC. Performance evaluation is carried through simulation using OPNET Modeler 9. 0. Simulation results show that the proposed handoff procedures in D-MDMN have better performance in terms of handoff latency, end-to-end delay and handoff scalability than that in UMTS. Performance evaluation of our proposed IP DiffServ video marking algorithm is also undertaken, which shows that it is more suitable for video streaming in IP mobile networks compared with the previously proposed DiffServ video marking algorithm (DVMA)

TCP flow aware adaptive path switching in diffserv enabled MPLS networks

Cataloged from PDF version of article.We propose an adaptive flow-level multi-path routing-based traffic engineering solution for an IP backbone network carrying TCP/IP traffic. Incoming TCP flows are switched between two explicitly routed paths, namely the primary and secondary paths (PP and SP), for resilience and potential goodput improvement at the TCP layer. In the proposed architecture, PPs receive a preferential treatment over SPs using differentiated services mechanisms. The reason for this choice is not for service differentiation but for coping with the detrimental knock-on effect stemming from the use of longer SP that is well known for conventional network load balancing algorithms. Moreover, both paths are congestion-controlled using Explicit Congestion Notification marking at the core and Additive Increase Multiplicative Decrease rate adjustment at the ingress nodes. The delay difference between PP and SP is estimated using two per-egress rate-controlling buffers maintained at the ingress nodes for each path, and this delay difference is used to determine the path over which a new TCP flow will be routed. We perform extensive simulations using ns-2 in order to demonstrate the viability of the proposed distributed adaptive multi-path routing method in terms of per-flow TCP goodput. The proposed solution consistently outperforms the single-path routing policy and provides substantial per-flow goodput gains under poor PP conditions. Moreover, highest goodput improvements under the proposed scheme are achieved by flows that receive the lowest goodputs with single-path routing, while the performance of the flows with high goodputs with single-path routing does not deteriorate with the proposed path switching technique. Copyright # 2011 John Wiley & Sons, Ltd

Multi Protocol Label Switching: Quality of Service, Traffic Engineering application, and Virtual Private Network application

This thesis discusses the QoS feature, Traffic Engineering (TE) application, and Virtual Private Network (VPN) application of the Multi Protocol Label Switching (MPLS) protocol. This thesis concentrates on comparing MPLS with other prominent technologies such as Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and Frame Relay (FR). MPLS combines the flexibility of Internet Protocol (IP) with the connection oriented approach of Asynchronous Transfer Mode (ATM) or Frame Relay (FR). Section 1 lists several advantages MPLS brings over other technologies. Section 2 covers architecture and a brief description of the key components of MPLS. The information provided in Section 2 builds a background to compare MPLS with the other technologies in the rest of the sections. Since it is anticipate that MPLS will be a main core network technology, MPLS is required to work with two currently available QoS architectures: Integrated Service (IntServ) architecture and Differentiated Service (DiffServ) architecture. Even though the MPLS does not introduce a new QoS architecture or enhance the existing QoS architectures, it works seamlessly with both QoS architectures and provides proper QoS support to the customer. Section 3 provides the details of how MPLS supports various functions of the IntServ and DiffServ architectures. TE helps Internet Service Provider (ISP) optimize the use of available resources, minimize the operational costs, and maximize the revenues. MPLS provides efficient TE functions which prove to be superior to IP and ATM/FR. Section 4 discusses how MPLS supports the TE functionality and what makes MPLS superior to other competitive technologies. ATM and FR are still required as a backbone technology in some areas where converting the backbone to IP or MPLS does not make sense or customer demands simply require ATM or FR. In this case, it is important for MPLS to work with ATM and FR. Section 5 highlights the interoperability issues and solutions for MPLS while working in conjunction with ATM and FR. In section 6, various VPN tunnel types are discussed and compared with the MPLS VPN tunnel type. The MPLS VPN tunnel type is concluded as an optimal tunnel approach because it provides security, multiplexing, and the other important features that are reburied by the VPN customer and the ISP. Various MPLS layer 2 and layer 3 VPN solutions are also briefly discussed. In section 7 I conclude with the details of an actual implementation of a layer 3 MPLS VPN solution that works in conjunction with Border Gateway Protocol (BGP)

Voice over IP

The area that this thesis covers is Voice over IP (or IP Telephony as it is sometimes called) over Private networks and not over the Internet. There is a distinction to be made between the two even though the term is loosely applied to both. IP Telephony over Private Networks involve calls made over private WANs using IP telephony protocols while IP Telephony over the Internet involve calls made over the public Internet using IP telephony protocols. Since the network is private, service is reliable because the network owner can control how resources are allocated to various applications, such as telephony services. The public Internet on the other hand is a public, largely unmanaged network that offers no reliable service guarantee. Calls placed over the Internet can be low in quality, but given the low price, some find this solution attractive. What started off as an Internet Revolution with free phone calls being offered to the general public using their multimedia computers has turned into a telecommunication revolution where enterprises are beginning to converge their data and voice networks into one network. In retrospect, an enterprise\u27s data networks are being leveraged for telephony. The communication industry has come full circle. Earlier in the decade data was being transmitted over the public voice networks and now voice is just another application which is/will be run over the enterprises existing data networks. We shall see in this thesis the problems that are encountered while sending Voice over Data networks using the underlying IP Protocol and the corrective steps taken by the Industry to resolve these multitudes of issues. Paul M. Zam who is collaborating in this Joint Thesis/project on VoIP will substantiate this theoretical research with his practical findings. On reading this paper the reader will gain an insight in the issues revolving the implementation of VoIP in an enterprises private network as well the technical data, which sheds more light on the same. Thus the premise of this joint thesis/project is to analyze the current status of the technology and present a business case scenario where an organization will be able to use this information

Pour un mécanisme de protection différenciée unique contre la gestion ainsi que les pannes : DiffServ*

L'avènement de l'Internet multiservice met fin à l'ère du réseautage de nature meilleur effort. Cette nouvelle caractéristique est très souhaitable et prometteuse sur plusieurs plans mais elle reste sujette à la capacité du réseau de protéger chaque catégorie de trafic selon sa priorité et ses exigences en qualité de service. Quand le réseau est déployé sur une infrastructure optique, une des préoccupations des plus importantes est sa capacité de survie et le maintien d'un service adéquat à toutes les applications suite à une panne physique. Nous savons qu'une simple coupure de fibre provoque des pertes énormes en capacité de transmission et si laissée sans surveillance, elle peut causer des dégradations majeures dans la qualité de service perçue par les usagers du réseau. Bien qu'il existe déjà des mécanismes de protection physique qui sont conçus spécifiquement pour remédier à de telles situations, ces options sont généralement très coûteuses et difficilement adaptable aux besoins variés de chaque classe de trafic d'un réseau multiserviceNous proposons alors un modèle innovateur de protection différenciée du trafic, DiffServ*, qui permet de répondre aux exigences particulières en qualité de service et de protection de chacune des classes de trafic et qui introduit une robustesse accrue et des économies importantes en matière d'utilisation de ressources d'un réseau IP/WDM. DiffServ* se distingue par l'utilisation combinée de l'architecture des services différenciées à la couche logique d'un réseau et de la technique d'agrégation de liens ou canaux disjoints à sa couche physiqueNotre modèle de protection différenciée du trafic en cas de pannes a été soumis à l'épreuve, nous avons utilisé la simulation pour étudier sa performance et nous l'avons comparé à un modèle de protection physique homologue, DiffProtect. Les résultats montrent que DiffServ* permet en moyenne de garantir une meilleure protection que DiffProtect en cas de pannes simples et multiples. DiffProtect n'est plus performant que dans certaines situations de pannes et de trafic très particulières. Une évaluation subséquente de la fiabilité d'un réseau qui utilise DiffServ*, une étude de coût de son déploiement et une étude de cas qui cible les réseaux MPLS-DiffServ TE confirment davantage la supériorité de DiffServ* par rapport à tout autre option de protection différenciée envisageableNous rappelons que DiffServ* se base sur les techniques de différenciation de service de la couche logique pour protéger le trafic en cas de pannes de composantes optiques. Ceci est inédit puisque ces mêmes techniques sont originalement conçues que pour protéger le trafic en cas de congestion dans la couche logique. Alors pour démontrer définitivement que DiffServ* est réalisable et fonctionnel nous réalisons une expérience de déploiement pratique de DiffServ* en laboratoire à l'aide d'équipements de communication réel. Malgré les divergences techniques entre la modélisation théorique de DiffServ* et de son implémentation, DiffServ* est démontré performant, fiable, économique et réalisable en pratiqueNous clôturons ce projet par une planification de déploiement ; cette dernière permet de généraliser le déploiement de DiffServ* à toute topologie IP/WDM et d'en dimensionner la couche logique. Notre procédure approche les situations qui requièrent la fiabilité spécifique de DiffProtect en offrant un modèle d'optimisation complet sur le déploiement de la protection MixProtect multicouche qui utilise DiffServ* et DiffProtect dans le même résea