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

Satellite Networks: Architectures, Applications, and Technologies

Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled

Renegotiable VBR service

In this work we address the problem of supporting the QoS requirements for applications while efficiently allocating the network resources. We analyse this problem at the source node where the traffic profile is negotiated with the network and the traffic is shaped according to the contract. We advocate VBR renegotiation as an efficient mechanism to accommodate traffic fluctuations over the burst time-scale. This is in line with the Integrated Service of the IETF with the Resource reSerVation Protocol (RSVP), where the negotiated contract may be modified periodically. In this thesis, we analyse the fundamental elements needed for solving the VBR renegotiation. A source periodically estimates the needs based on: (1) its future traffic, (2) cost objective, (3) information from the past. The issues of this estimation are twofold: future traffic prediction given a prediction, the optimal change. In the case of a CBR specification the optimisation problem is trivial. But with a VBR specification this problem is complex because of the multidimensionality of the VBR traffic descriptor and the non zero condition of the system at the times where the parameter set is changed. We, therefore, focus on the problem of finding the optimal change for sources with pre-recorded or classified traffic. The prediction of the future traffic is out of the scope of this thesis. Traditional existing models are not suitable for modelling this dynamic situation because they do not take into account the non-zero conditions at the transient moments. To address the shortfalls of the traditional approaches, a new class of shapers, the time varying leaky bucket shaper class, has been introduced and characterised by network calculus. To our knowledge, this is the first model that takes into account non-zero conditions at the transient time. This innovative result forms the basis of Renegotiable VBR Service (RVBR). The application of our RVBR mathematical model to the initial problem of supporting the applications' QoS requirements while efficiently allocating the network resources results in simple, efficient algorithms. Through simulation, we first compare RVBR service versus VBR service and versus renegotiable CBR service. We show that RVBR service provides significant advantages in terms of resource costs and resource utilisation. Then, we illustrate that when the service assumes zero conditions at the transient time, the source could potentially experience losses in the case of policing because of the mismatch between the assumed bucket and buffer level and the policed bucket and buffer level. As an example of RVBR service usage, we describe the simulation of RVBR service in a scenario where a sender transmits a MPEG2 video over a network using RSVP reservation protocol with Controlled-Load service. We also describe the implementation design of a Video on Demand application, which is the first example of an RVBR-enabled application. The simulation and experimentation results lead us to believe that RVBR service provides an adequate service (in terms of QoS guaranteed and of efficient resource allocation) to sources with pre-recorded or classified traffic

Application of Asynchronous Transfer Mode (Atm) technology to Picture Archiving and Communication Systems (Pacs): A survey

Broadband Integrated Services Digital Network (R-ISDN) provides a range of narrowband and broad-band services for voice, video, and multimedia. Asynchronous Transfer Mode (ATM) has been selected by the standards bodies as the transfer mode for implementing B-ISDN; The ability to digitize images has lead to the prospect of reducing the physical space requirements, material costs, and manual labor of traditional film handling tasks in hospitals. The system which handles the acquisition, storage, and transmission of medical images is called a Picture Archiving and Communication System (PACS). The transmission system will directly impact the speed of image transfer. Today the most common transmission means used by acquisition and display station products is Ethernet. However, when considering network media, it is important to consider what the long term needs will be. Although ATM is a new standard, it is showing signs of becoming the next logical step to meet the needs of high speed networks; This thesis is a survey on ATM, and PACS. All the concepts involved in developing a PACS are presented in an orderly manner. It presents the recent developments in ATM, its applicability to PACS and the issues to be resolved for realising an ATM-based complete PACS. This work will be useful in providing the latest information, for any future research on ATM-based networks, and PACS

Netzwerk-Management und Hochgeschwindigkeits- Kommunikation. Teil XV. Seminar WS 1996/97

Der Interne Bericht enthaelt die Beitraege zum Seminar "Netzwerk-Management und Hochgeschwindigkeits-Kommunikation", das im Wintersemester 1996/97 zum fuenfzehnten Mal stattgefunden hat. Die Themenauswahl kann grob in folgende vier Bloecke gegliedert werden: 1. Ein Block ist der Mobilkommunikation gewidmet. Hier werden die aktuellen Entwicklungen zuerst anhand von UMTS aufgezeigt, einem europaeischen Projekt zur Standardisierung eines umfassenden Mobilfunksystems der 3. Generation. Anschliessend folgen Beitraege zur Technik des digitalen Radiosystems DAB (das auch als Datenverteildienst genutzt werden kann) sowie zum "Drahtlosen ATM". 2. Ein zweiter Block beschaeftigt sich mit grundlegenden Techniken in ATM-Netzwerken. Hier werden zum einen Routing-Mechanismen vorgestellt und zum anderen der ABR-Dienst erlaeutert. 3. Der dritte Block umfasst den Themenbereich Internet. Hier werden neuere Entwicklungen anhand von IPv6 und TCPng aufgezeigt. Schliesslich werden noch Charakteristiken des Multicast Backbone (MBone) untersucht. 4. Im vierten Block werden Netztechnologien im LAN/MAN-Bereich vorgestellt. Hier werden die Standards zum Fast Ethernet und Grundlagen zum Thema "Corporate Networks" praesentiert

Scalable QoS routing in MPLS networks using mobile code

In a continually evolving Internet, tools such as Q u a lity o f Service ro u tin g must be used in order to accommodate user demands. However, deploying and developing QoS routing in the legacy Internet is difficult. Multiprotocol Label Switching (MPLS) facilitates the deployment of QoS routing, due to its separation of functions between the control and forwarding plane. Developing QoS routing raises scalability issues within very large networks. I propose overcoming these issues by using topology aggregation and distributed routing based on modem techniques such as active networks and mobile agents. However, topology aggregation introduces inaccuracy, which has a negative impact on QoS routing performance. To avoid such problems I propose a hierarchical routing protocol, called Macro-routing, which by using distributed route computation is able to process more detailed information and thus to use the most accurate aggregation technique, i.e. Full-Mesh. Therefore, the protocol is more likely to find the best path between source and destination, and can also find more than one available path. QoS routing, which is used for finding feasible paths that simultaneously satisfy multiple constraints, is also called multiple-constrained routing and is an NP-complete problem. The difficulty of solving such problems increases in a hierarchical context, where aggregation techniques influence the path computation process. I propose a new aggregation technique which allows the selection of multiple paths that satisfy multiple QoS constraints. This reduces the probability of a false negative, i.e., of the routing algorithm incorrectly reporting that no path satisfying the constraints exists. This aggregation technique is called extended full-mesh (EFM) and is intended for use with the Macro-routing protocol. Deploying these protocols in the Internet will allow multi-constrained routing to be practically implemented on large networks

Scalabale Group Communication Support for ATM Networks

In dieser Arbeit wird ein Ansatz vorgestellt, der eine skalierbare Gruppenkommunikationsunterstützung für ATM-Netze (SkaGAN) ermöglicht. Die herkömmliche rechnergestützte Kommunikation findet zwischen einem Sender und einem Empfänger statt. Die Gruppenkommunikation erweitert diese Form und erlaubt einer Gruppe von Rechnern untereinander zu kommunizieren. Diese Dissertation legt dabei den Fokus auf die ATM-Technologie (Asynchronous Transfer Mode), die keine akzeptable Gruppenkommunikationsunterstützung anbietet. Heutzutage wird ATM hauptsächlich in Backbone-Netzen eingesetzt, womit sich auch diese Arbeit auseinandersetzt. Der Schwerpunkt bei SkaGAN ist die Skalierbarkeit in Bezug auf Netzwerk- und Gruppengröße. Für den Bereich der lokalen ATM-Netze wird ebenfalls ein Lösungsvorschlag präsentiert, der eine Lastverteilung aktiver Gruppenteilnehmer auf mehrere Server beinhaltet. Der Lösungsansatz von SkaGAN für ATM-Weitverkehrsnetze orientiert sich an dem PNNI-Routingprotokoll und basiert auf einem hierarchischen Schema. Für die Verwaltung der Gruppen wird eine Baumhierarchie eingesetzt, die eine erhebliche Reduktion des Signalisierungsaufwandes und eine gute Skalierbarkeit ermöglicht. Für den Datentransfer zwischen den Gruppenteilnehmern wird ebenfalls eine Baumstruktur eingesetzt, die sich dynamisch an Änderungen in den Gruppen anpassen kann. Dabei wird die Anzahl der benötigten Zwischensysteme möglichst gering gehalten und die Lokalität der Teilnehmer berücksichtigt. Damit konnte auch in diesen Bereich eine gute Skalierbarkeit bei der Gruppenkommunikation erreicht werden.In this work, an approach is introduced, that enables scaleable group communication support for ATM networks (SkaGAN). The conventional computer supported communication takes place between one sender and one receiver. Group communication expands this form and allows a group of computers to communicate among each other. This dissertation puts its focus on the ATM technology (Asynchronous Transfer Mode), which offers no acceptable group communication support. Nowadays ATM is mainly utilized in backbone networks, wherewith this work deals. The focal point in SkaGAN is the scalability with regard to network and group sizes. In the area of local ATM networks a solution proposal is presented, that includes a load distribution of active group members on several servers. The approach for the solution of SkaGAN for ATM wide area networks orients itself on the PNNI routing protocol and is based on a hierarchical scheme. For the administration of the groups, a tree hierarchy is inserted, that enables a considerable reduction of the signaling expenses and a good scalability. For the data transfer between the group members also a tree structure is used, that can adapt itself dynamically to group changes. Thereby the amount of necessary intermediate systems is as small as possible and the location of the group members will be considered. Therewith also in this area a good scalability could be reached in the group communication