Towards Scalable MANETs

International audienceIn the near-future, self-organized networking is expected to become an important component in ITS, and in the Internet architecture in general. An essential challenge concerning the integration of this new component is the accomplishment of scalable and efficient mobile ad hoc routing. This paper overviews considerations relative to the design of such MANET protocols inside the framework provided by the IETF, stating the need for new hybrid protocols and architecture which offer a gradual transition from "traditional" MANET routing towards scalable MANET routing integrated in the Internet. This paper also proposes a tentative solution in this domain: DHT-OLSR, based on OLSR enhanced with dynamic clustering and distributed hash table routing

OSHI - Open Source Hybrid IP/SDN networking (and its emulation on Mininet and on distributed SDN testbeds)

The introduction of SDN in IP backbones requires the coexistence of regular IP forwarding and SDN based forwarding. The former is typically applied to best effort Internet traffic, the latter can be used for different types of advanced services (VPNs, Virtual Leased Lines, Traffic Engineering...). In this paper we first introduce the architecture and the services of an "hybrid" IP/SDN networking scenario. Then we describe the design and implementation of an Open Source Hybrid IP/SDN (OSHI) node. It combines Quagga for OSPF routing and Open vSwitch for OpenFlow based switching on Linux. The availability of tools for experimental validation and performance evaluation of SDN solutions is fundamental for the evolution of SDN. We provide a set of open source tools that allow to facilitate the design of hybrid IP/SDN experimental networks, their deployment on Mininet or on distributed SDN research testbeds and their test. Finally, using the provided tools, we evaluate key performance aspects of the proposed solutions. The OSHI development and test environment is available in a VirtualBox VM image that can be downloaded.Comment: Final version (Last updated August, 2014

Hybrid FPGA: Architecture and Interface

Hybrid FPGAs (Field Programmable Gate Arrays) are composed of general-purpose logic resources with different granularities, together with domain-specific coarse-grained units. This thesis proposes a novel hybrid FPGA architecture with embedded coarse-grained Floating Point Units (FPUs) to improve the floating point capability of FPGAs. Based on the proposed hybrid FPGA architecture, we examine three aspects to optimise the speed and area for domain-specific applications. First, we examine the interface between large coarse-grained embedded blocks (EBs) and fine-grained elements in hybrid FPGAs. The interface includes parameters for varying: (1) aspect ratio of EBs, (2) position of the EBs in the FPGA, (3) I/O pins arrangement of EBs, (4) interconnect flexibility of EBs, and (5) location of additional embedded elements such as memory. Second, we examine the interconnect structure for hybrid FPGAs. We investigate how large and highdensity EBs affect the routing demand for hybrid FPGAs over a set of domain-specific applications. We then propose three routing optimisation methods to meet the additional routing demand introduced by large EBs: (1) identifying the best separation distance between EBs, (2) adding routing switches on EBs to increase routing flexibility, and (3) introducing wider channel width near the edge of EBs. We study and compare the trade-offs in delay, area and routability of these three optimisation methods. Finally, we employ common subgraph extraction to determine the number of floating point adders/subtractors, multipliers and wordblocks in the FPUs. The wordblocks include registers and can implement fixed point operations. We study the area, speed and utilisation trade-offs of the selected FPU subgraphs in a set of floating point benchmark circuits. We develop an optimised coarse-grained FPU, taking into account both architectural and system-level issues. Furthermore, we investigate the trade-offs between granularities and performance by composing small FPUs into a large FPU. The results of this thesis would help design a domain-specific hybrid FPGA to meet user requirements, by optimising for speed, area or a combination of speed and area

Asynchronous Graph Pattern Matching on Multiprocessor Systems

Pattern matching on large graphs is the foundation for a variety of application domains. Strict latency requirements and continuously increasing graph sizes demand the usage of highly parallel in-memory graph processing engines that need to consider non-uniform memory access (NUMA) and concurrency issues to scale up on modern multiprocessor systems. To tackle these aspects, graph partitioning becomes increasingly important. Hence, we present a technique to process graph pattern matching on NUMA systems in this paper. As a scalable pattern matching processing infrastructure, we leverage a data-oriented architecture that preserves data locality and minimizes concurrency-related bottlenecks on NUMA systems. We show in detail, how graph pattern matching can be asynchronously processed on a multiprocessor system.Comment: 14 Pages, Extended version for ADBIS 201

Congestion Reduction in Traditional and New Routing Architectures

In dense integrated circuit designs, management of routing congestion is essential; an over congested design may be unroutable. Many factors influence congestion: placement, routing, and routing architecture all contribute. Previous work has shown that different placement tools can have substantially different demands for each routing layer; our objective is to develop methods that allow “tuning” of interconnect topologies to match routing resources. We focus on congestion minimization for both Manhattan and non-Manhattan routing architectures, and have two main contributions. First, we combine prior heuristics for non-Manhattan Steiner trees and Preferred Direction Steiner trees into a hybrid approach that can handle arbitrary routing directions, via minimization, and layer assignment of edges simultaneously. Second, we present an effective method to adjust Steiner tree topologies to match routing demand to resource, resulting in lower congestion and better routability

The Road Ahead for Networking: A Survey on ICN-IP Coexistence Solutions

In recent years, the current Internet has experienced an unexpected paradigm shift in the usage model, which has pushed researchers towards the design of the Information-Centric Networking (ICN) paradigm as a possible replacement of the existing architecture. Even though both Academia and Industry have investigated the feasibility and effectiveness of ICN, achieving the complete replacement of the Internet Protocol (IP) is a challenging task. Some research groups have already addressed the coexistence by designing their own architectures, but none of those is the final solution to move towards the future Internet considering the unaltered state of the networking. To design such architecture, the research community needs now a comprehensive overview of the existing solutions that have so far addressed the coexistence. The purpose of this paper is to reach this goal by providing the first comprehensive survey and classification of the coexistence architectures according to their features (i.e., deployment approach, deployment scenarios, addressed coexistence requirements and architecture or technology used) and evaluation parameters (i.e., challenges emerging during the deployment and the runtime behaviour of an architecture). We believe that this paper will finally fill the gap required for moving towards the design of the final coexistence architecture.Comment: 23 pages, 16 figures, 3 table

PIM-SM = Protocol Independent Multicast- Sparse Mode

This paper proposes a design for IP multicast routing in hybrid satellite networks. The emergence of IP multicast for Internet group communication has placed focus on communication satellites as an efficient way to extend the multicast services for groups with distributed membership in wide-area networks. This poses interesting challenges for routing. Hybrid satellite networks can have both wired and wireless links and also combine different link-layer technologies like Ethernet and ATM. No proposed IP multicast routing protocol for wired networks offers an integrated solution for such networks. This paper attempts to provide a solution by proposing a design for IP multicast routing in wide-area networks that have terrestrial Ethernet LANs interconnected by A TM-based satellite channels. The paper reviews the multicast services offered by IP and A TM, and proposes a multicast routing framework that combines PIM-SM protocol for terrestrial multicasting with the A TM MARS and VC mesh architecture for multicast routing over the satellite links. Modifications are made to the standard protocols to suit the unique needs of the network being considered. The feasibility of the proposed design is tested by performing simulations. The proposed framework is presented in detail, along with analysis and simulation results