System architecture and hardware implementations for a reconfigurable MPLS router

With extremely wide bandwidth and good channel properties, optical fibers have brought fast and reliable data transmission to today’s data communications. However, to handle heavy traffic flowing through optical physical links, much faster processing speed is required or else congestion can take place at network nodes. Also, to provide people with voice, data and all categories of multimedia services, distinguishing between different data flows is a requirement. To address these router performance, Quality of Service /Class of Service and traffic engineering issues, Multi-Protocol Label Switching (MPLS) was proposed for IP-based Internetworks. In addition, routers flexible in hardware architecture in order to support ever-evolving protocols and services without causing big infrastructure modification or replacement are also desirable. Therefore, reconfigurable hardware implementation of MPLS was proposed in this project to obtain the overall fast processing speed at network nodes. The long-term goal of this project is to develop a reconfigurable MPLS router, which uniquely integrates the best features of operations being conducted in software and in run-time-reconfigurable hardware. The scope of this thesis includes system architecture and service algorithm considerations, Verilog coding and testing for an actual device. The hardware and software co-design technique was used to partition and schedule the protocol code for execution on both a general-purpose processor and stream-based hardware. A novel RPS scheme that is practically easy to build and can realize pipelined packet-by-packet data transfer at each output was proposed to take the place of the traditional crossbar switching. In RPS, packets with variable lengths can be switched intelligently without performing packet segmentation and reassembly. Primary theoretical analysis of queuing issues was discussed and an improved multiple queue service scheduling policy UD-WRR was proposed, which can reduce packet-waiting time without sacrificing the performance. In order to have the tests carried out appropriately, dedicated circuitry for the MPLS functional block to interface a specific MAC chip was implemented as well. The hardware designs for all functions were realized with a single Field Programmable Gate Array (FPGA) device in this project. The main result presented in this thesis was the MPLS function implementation realizing a major part of layer three routing at the reconfigurable hardware level, which advanced a great step towards the goal of building a router that is both fast and flexible

The troubled journey of QoS: From ATM to content networking, edge-computing and distributed internet governance

Network Quality of Service (QoS) and the associated user Quality of Experience (QoE) have always been the networking “holy grail” and have been sought after through various different approaches and networking technologies over the last decades. Despite substantial amounts of effort invested in the area, there has been very little actual deployment of mechanisms to guarantee QoS in the Internet. As a result, the Internet is largely operating on a “best effort” basis in terms of QoS. Here, we attempt a historical overview in order to better understand how we got to the point where we are today and consider the evolution of QoS/QoE in the future. As we move towards more demanding networking environments where enormous amounts of data is produced at the edge of the network (e.g., from IoT devices), computation will also need to migrate to the edge in order to guarantee QoS. In turn, we argue that distributed computing at the edge of the network will inevitably require infrastructure decentralisation. That said, trust to the infrastructure provider is more difficult to guarantee and new components need to be incorporated into the Internet landscape in order to be able to support emerging applications, but also achieve acceptable service quality. We start from the first steps of ATM and related IP-based technologies, we consider recent proposals for content-oriented and Information-Centric Networking, mobile edge and fog computing, and finally we see how distributed Internet governance through Distributed Ledger Technology and blockchains can influence QoS in future networks

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

Netzwerkmanagement und Hochleistungskommunikation. Teil XXIV. Seminar SS 2001

This Technical Report includes student papers produced within a seminar of "Network Management and High Performance Communications". For the 24nd time this seminar has attracted a large number of diligent students, proving the broad interest in topics of network management and high performance ommunications. The topics of this report may be coarsely divided into two blocks: One block is devoted to high speed and high performance technology. At first, the concept of modern High Speed Switches and Routers with quality-of-service support is described. Subsequently, Efficient Methods and Algorithms for Routing Table Lookups as well as Classification of IP Packets and multiprotocol Label Switching (MPLS) are presented. A second block deals with various topics such as wireless communications, network management and security. The first article shows advantages of the Policy-based Networks to manage todays networks. Furthermore, Security Extensions of DNS for secure use of the domain name service are examined and presented. The next article describes how to use mobility profiles in mobile ad-hoc networks. Methods for watermarking of multimedia data are discussed in a subsequent article. Moreover, Technical Challenges and Solutions for IP-telephony are also presented, whereby the Stream Control Transmission Protocol is described separately as an approach to achieve a better transport of signaling messages over the Internet. The last article deals with group communication and shows New Approaches for Multicast Routing as well as an overview of some Multicast transport protocols

Enabling architectures for QoS provisioning

Nowadays, new multimedia services have been deployed with stringent requirements for Quality of Service (QoS). The QoS provisioning is faced with the heterogeneity of system components. This thesis presents two research: on architectures for QoS management at the application layer, fulfilled mainly by software components; and on distributed software architectures for routing devices providing desired QoS at the underlying communication layer. At the application layer, the QoS architecture we propose, based on the Quality Driven Delivery (QDD) framework, deals with the increasing amount of QoS information of a distributed system. Based on various QoS information models we define for key actors of a distributed system, a QoS information base is generated using QoS information collecting and analysis tools. To translate QoS information among different components, we propose mechanisms to build QoS mapping rules from statistical data. Experiments demonstrate that efficient QoS decisions can be made effectively regarding the contribution of all system components with the help of the QoS information management system. At the underlying layer, we investigate distributed and scalable software architectures for QoS-enabled devices. Due to the huge volume of traffic to be switched, the traditional software model used for current generation routers, where the control card of the router performs all the processing tasks, is no longer appropriate in the near future. We propose a new scalable and distributed architecture to fully exploit the hardware platforms of the next generation routers, and to improve the quality of routers, particularly with respect to scalability and to a lesser extent to resiliency and availability. Our proposal is a distributed software framework where control tasks are shared among the control and line cards of the router. Specific architectures for routing, signaling protocols and routing table management are developed. We investigate the challenges for such distributed architectures and proposed various solutions to overcome them. Based on a general distributed software framework, an efficient scalable distributed architecture for MPLS/LDP and different scalable distributed schemes for the routing table manager (RTM) are developed. We also evaluate the performance of proposed distributed schemes and discuss where to deploy these architectures depending on the type of routers (i.e., their hardware capacity

Paketverarbeitende Systeme – Algorithmen und Architekturen für hohe Verarbeitungsgeschwindigkeiten

Paketverarbeitende Systeme basieren auf zwei wichtigen Bereichen: der eigentlichen Paketverarbeitung und der Paketklassifizierung. Zur Optimierung der Paketverarbeitung wurde eine FPGA-basierte Architektur für funktionale Module entwickelt, auf deren Basis verschiedene Funktionen für den Einsatz im Teilnehmerzugangsnetzwerk realisiert wurden. Hash-basierte Klassifizierungsalgorithmen und –architekturen sind grundsätzlich für die Paketklassifizierung geeignet. Zur Optimierung dieser Klasse von Algorithmen wurde eine evolvierbare Hashfunktionsarchitektur entwickelt.Packet processing systems base on two important areas: ultimate packet and packet classification. For optimization of packet processing an FPGA-based architecture for functional modules has been developed. For application in Access Network, different functional modules have been developed. Hash-based classification algorithms and architectures are appropriate for fast packet classification. For optimization of this class of algorithms, an evolvable architecture for hash functions has been developed

Aspects of proactive traffic engineering in IP networks

To deliver a reliable communication service over the Internet it is essential for the network operator to manage the traffic situation in the network. The traffic situation is controlled by the routing function which determines what path traffic follows from source to destination. Current practices for setting routing parameters in IP networks are designed to be simple to manage. This can lead to congestion in parts of the network while other parts of the network are far from fully utilized. In this thesis we explore issues related to optimization of the routing function to balance load in the network and efficiently deliver a reliable communication service to the users. The optimization takes into account not only the traffic situation under normal operational conditions, but also traffic situations that appear under a wide variety of circumstances deviating from the nominal case. In order to balance load in the network knowledge of the traffic situations is needed. Consequently, in this thesis we investigate methods for efficient derivation of the traffic situation. The derivation is based on estimation of traffic demands from link load measurements. The advantage of using link load measurements is that they are easily obtained and consist of a limited amount of data that need to be processed. We evaluate and demonstrate how estimation based on link counts gives the operator a fast and accurate description of the traffic demands. For the evaluation we have access to a unique data set of complete traffic demands from an operational IP backbone. However, to honor service level agreements at all times the variability of the traffic needs to be accounted for in the load balancing. In addition, optimization techniques are often sensitive to errors and variations in input data. Hence, when an optimized routing setting is subjected to real traffic demands in the network, performance often deviate from what can be anticipated from the optimization. Thus, we identify and model different traffic uncertainties and describe how the routing setting can be optimized, not only for a nominal case, but for a wide range of different traffic situations that might appear in the network. Our results can be applied in MPLS enabled networks as well as in networks using link state routing protocols such as the widely used OSPF and IS-IS protocols. Only minor changes may be needed in current networks to implement our algorithms. The contributions of this thesis is that we: demonstrate that it is possible to estimate the traffic matrix with acceptable precision, and we develop methods and models for common traffic uncertainties to account for these uncertainties in the optimization of the routing configuration. In addition, we identify important properties in the structure of the traffic to successfully balance uncertain and varying traffic demands

FPGA-based architectures for next generation communications networks

This engineering doctorate concerns the application of Field Programmable Gate Array (FPGA) technology to some of the challenges faced in the design of next generation communications networks. The growth and convergence of such networks has fuelled demand for higher bandwidth systems, and a requirement to support a diverse range of payloads across the network span. The research which follows focuses on the development of FPGA-based architectures for two important paradigms in contemporary networking - Forward Error Correction and Packet Classification. The work seeks to combine analysis of the underlying algorithms and mathematical techniques which drive these applications, with an informed approach to the design of efficient FPGA-based circuits