IP and ATM - a position paper

This paper gives a technical overview of different networking technologies, such as the Internet, ATM. It describes different approaches of how to run IP on top of an ATM network, and assesses their potential to be used as an integrated services network

ENVIRONMENTAL-IMPACT EXTENSIONS FOR TRACEROUTE AND PING

The computer network diagnostic facilities traceroute and ping are arguably some of the most used networking troubleshooting tools. Augmenting those facilities to present environmental and sustainability data and metadata would contribute to gain visibility on “green metrics” on the Internet, an objective mentioned in the Internet Engineering Task Force (IETF) E-Impact initiative. Techniques are presented herein that support Environmental-Impact extensions (or “E-Impact” extensions for short) to both traceroute and ping. The presented extensions are backwards compatible and potentially provide per-hop (e.g., per networking topological node) power metrics, estimated greenhouse gas (GHG) emission numbers, and potentially other current or future sustainability metrics. Aspects of the presented techniques support a combination of in-packet (e.g., Internet Control Message Protocol (ICMP) extensions) plus out-of-band (e.g., out of band database lookup or application programming interface (API) calls from a host) methods that, together, yield the above-described new metrics. The presented techniques are useful not only in a transactional setting (e.g., a user desired to find some information so they issue a traceroute or a ping request) but they may also be run periodically in a mesh across the Internet or across an administrative domain to map out environmental-impact metrics, including energy usage, power and normalized power, and estimated GHG emissions

IP and ATM - current evolution for integrated services

Current and future applications make use of different technologies as voice, data, and video. Consequently network technologies need to support them. For many years, the ATM based Broadband-ISDN has generally been regarded as the ultimate networking technology, which can integrate voice, data, and video services. With the recent tremendous growth of the Internet and the reluctant deployment of public ATM networks, the future development of ATM seems to be less clear than it used to be. In the past IP provided (and was though to provide) only best effort services, thus, despite its world wide diffution, was not considered as a network solution for multimedia application. Currently many of the IETF working groups work on areas related to integrated services, and IP is also proposing itself as networking technology for supporting voice, data, and video services. This paper give a technical overview on the competing integrated services network solutions, such as IP, ATM and the different available and emerging technologies on how to run IP over ATM, and tries to identify their potential and shortcomings

Performance Evaluation of MPLS in a Virtualized Service Provider Core (with/without Class of Service)

The last decade has witnessed a major change in the types of traffic scaling the Internet. With the development of real-time applications several challenges were faced within traditional IP networks. Some of these challenges are delay, increased costs faced by the service provider and customer, limited scalability, separate infrastructure costs and high administrative overheads to manage large networks etc. To combat these challenges, researchers have steered towards finding alternate solutions. Over the recent years, we have seen an introduction of a number of virtualized platforms and solutions being offered in the networking industry. Virtual load balancers, virtual firewalls, virtual routers, virtual intrusion detection and preventions systems are just a few examples within the Network Function Virtualization world! Service Providers are trying to find solutions where they could reduce operational expenses while at the same time meet the growing bandwidth demands of their customers. The main aim of this thesis is to evaluate the performance of voice, data and video traffic in a virtualized service provider core. Observations are made on how these traffic types perform on congested vs uncongested links and how Quality of Service treats traffic in a virtualized Service Provider Core using Round Trip Time as a performance metric. This thesis also tries to find if resiliency features such as Fast Reroute provide an additional advantage in failover scenarios within virtualized service provider cores. Juniper Networks vSRX are used to replicate virtual routers in a virtualized service provider core. Twenty-Four tests are carried out to gain a better understanding of how real-time applications and resiliency methods perform in virtualized networks. It is observed that a trade-off exists when introducing QoS on congested primary and secondary label switched paths. What can be observed thru the graphs is having Quality of Service enabled drops more packets however gives us the advantage of lower Round Trip Time for in-profile traffic. On the hand, having Quality of Service disabled, permits more traffic but leads to bandwidth contention between the three traffic classes leading to higher Round-Trip Times. The true benefit of QoS is seen in traffic congestion scenarios. The test bed built in this thesis, shows us that Fast Reroute does not add a significant benefit to aid in the reduction of packet loss during failover scenarios between primary and secondary paths. However, in certain scenarios fast reroute does seem to reduce packet loss specifically for data traffic

IP and ATM integration: A New paradigm in multi-service internetworking

ATM is a widespread technology adopted by many to support advanced data communication, in particular efficient Internet services provision. The expected challenges of multimedia communication together with the increasing massive utilization of IP-based applications urgently require redesign of networking solutions in terms of both new functionalities and enhanced performance. However, the networking context is affected by so many changes, and to some extent chaotic growth, that any approach based on a structured and complex top-down architecture is unlikely to be applicable. Instead, an approach based on finding out the best match between realistic service requirements and the pragmatic, intelligent use of technical opportunities made available by the product market seems more appropriate. By following this approach, innovations and improvements can be introduced at different times, not necessarily complying with each other according to a coherent overall design. With the aim of pursuing feasible innovations in the different networking aspects, we look at both IP and ATM internetworking in order to investigating a few of the most crucial topics/ issues related to the IP and ATM integration perspective. This research would also address various means of internetworking the Internet Protocol (IP) and Asynchronous Transfer Mode (ATM) with an objective of identifying the best possible means of delivering Quality of Service (QoS) requirements for multi-service applications, exploiting the meritorious features that IP and ATM have to offer. Although IP and ATM often have been viewed as competitors, their complementary strengths and limitations from a natural alliance that combines the best aspects of both the technologies. For instance, one limitation of ATM networks has been the relatively large gap between the speed of the network paths and the control operations needed to configure those data paths to meet changing user needs. IP\u27s greatest strength, on the other hand, is the inherent flexibility and its capacity to adapt rapidly to changing conditions. These complementary strengths and limitations make it natural to combine IP with ATM to obtain the best that each has to offer. Over time many models and architectures have evolved for IP/ATM internetworking and they have impacted the fundamental thinking in internetworking IP and ATM. These technologies, architectures, models and implementations will be reviewed in greater detail in addressing possible issues in integrating these architectures s in a multi-service, enterprise network. The objective being to make recommendations as to the best means of interworking the two in exploiting the salient features of one another to provide a faster, reliable, scalable, robust, QoS aware network in the most economical manner. How IP will be carried over ATM when a commercial worldwide ATM network is deployed is not addressed and the details of such a network still remain in a state of flux to specify anything concrete. Our research findings culminated with a strong recommendation that the best model to adopt, in light of the impending integrated service requirements of future multi-service environments, is an ATM core with IP at the edges to realize the best of both technologies in delivering QoS guarantees in a seamless manner to any node in the enterprise

Revealing and Characterizing MPLS Networks

The Internet is a wide network of computers in constant evolution. Each year, more and more organizations are connected to this worldwide network. Each of them has its own structure and administration that are not publicly revealed for economical, political, and security reasons. Consequently, our perception of the Internet structure, and more specifically, its topology, is incomplete. In order to balance this lack of knowledge, the research community relies on network measurements. Most of the time, they are performed based on the well-known tool traceroute. However, in practice, an operator may privilege other technologies than IP to forward packets inside its network. MultiProtocol Label Switching (MPLS) is one them. Even if it is heavily deployed by operators, it has not been really investigated by researchers. Prior to this thesis, only two studies focused on the identification of MPLS tunnels in traceroute data. Moreover, while one of them does not take all possible scenarios into account, the other lack of precision in some of its models. In addition, MPLS tunnels may hide their content to traceroute. Topologies inferred from such data may thus contain false links or nodes with an artificially high degree, leading so to biases in standard graph metrics used to model the network. Even if some researchers already tried to tackle this issue, the revelation of hidden MPLS devices in traceroute data is still an open question. This thesis aims at characterizing MPLS in two different ways. On the one hand, at an architectural level, we will analyze in detail its deployment and use in both IPv4 and IPv6 networks in order to improve its state-of-the-art view. We will show that, in practice, more than one IPv4 trace out of two crosses at least one MPLS tunnel. We will also see that, even if this protocol can simplify the internal architecture of transit networks, it also allows some operators to perform traffic engineering in their domain. On the other hand, MPLS will be studied from a measurement point of view. We will see that routers from different manufacturers may have distinct default behaviors regarding to MPLS, and that these specific behaviors can be exploited to identify MPLS tunnels during traceroute measurements. More precisely, we will focus on new methods able to infer the presence of tunnels that are invisible in traceroute outputs, as well as on mechanisms to reveal their content. We will also show that they can be used in order to improve the inference of Internet graph properties, such as path lengths and node degrees. Finally, these techniques will be integrated into Trace the Naughty Tunnels (TNT), a traceroute extension able to identify all types of MPLS tunnels along a path towards a destination. We will prove that this tool can be used in order to get a detailed quantification of MPLS tunnels in the worldwide network. TNT is publicly available, and can therefore be part of many future studies conducted by the research community.Internet est un immense réseau informatique en constante évolution. Chaque année, de plus en plus d’organisations s’y connectent. Chacune d’elles est gérée et administrée indépendamment des autres. En pratique, l’architecture interne de leur réseau n’est pas rendue publique pour des raisons politiques, économiques, ou de sécurité. Par conséquent, notre perception de la structure d’Internet, et plus particulièrement de sa topologie, est incomplète. Afin de pallier ce manque de connaissance, la communauté de la recherche s’appuie sur des mesures de réseau. La plupart du temps, elles sont réalisées avec l’outil traceroute. Cependant, des technologies autres que IP peuvent être privilégiées pour transférer les paquets dans un réseau. MultiProtocol Label Switching (MPLS) est l’une d’entre elles. Même si cette technologie est largement déployée dans Internet, elle n’est pas bien étudiée par les chercheurs. Avant cette thèse, seulement deux travaux se sont intéressés à l’identification d’MPLS dans les données collectées avec traceroute. Alors que le premier ne prend pas en compte tous les scénarios possibles, le second propose des modèles qui manquent de précision. De plus, les tunnels MPLS peuvent dissimuler leur contenu à traceroute. Les topologies inférées sur base de ces données peuvent donc contenir de faux liens, ou des noeuds avec un degré anormalement élevé. Les différentes modélisations d’Internet qui en résultent peuvent alors être biaisées. Aujourd’hui, la question de la révélation des routeurs MPLS qui sont invisibles dans les données de mesure n’est toujours pas résolue, même si certains chercheurs ont déjà proposé quelques méthodes pour y parvenir. Cette thèse a pour but de caractériser MPLS de deux manières différentes. Dans un premier temps, au niveau architectural, nous analyserons en détail son déploiement et son utilisation dans les réseaux IPv4 et IPv6 afin d’améliorer l’état de l’art. Nous montrerons qu’en pratique, plus d’une trace IPv4 sur deux traverse au moins un tunnel MPLS. Nous découvrirons également que bien que ce protocole peut être utilisé pour simplifier l’architecture interne des réseaux de transit, il peut aussi être déployé pour la mise en place de solutions d’ingénierie de trafic. Dans un second temps, MPLS sera étudié d’un point de vue mesure. Nous verrons que les comportements par défaut liés au protocole varient d’un fabricant de routeur à l’autre, et qu’ils peuvent être exploités afin d’identifier les tunnels MPLS dans les données traceroute. Plus précisément, nous découvrirons de nouvelles méthodes capables d’inférer la présence de tunnels invisibles avec traceroute, ainsi que de nouvelles techniques pour révéler leur contenu. Nous montrerons également qu’elles peuvent être utilisées afin d’améliorer la modélisation d’Internet. Pour terminer, ces techniques seront intégrées à Trace the Naughty Tunnels (TNT), une extension de traceroute qui permet d’identifier tous les types de tunnels MPLS le long du chemin vers une destination. Nous prouverons que cet outil peut être utilisé pour obtenir des statistiques détaillées sur le déploiement d’MPLS sur Internet. TNT est disponible publiquement, et peut donc être librement exploité par la communauté de la recherche pour de multiples futures études