Evaluation of tree-based routing Ethernet

Tree-based Routing (TRE) revisits Tree-based Routing Architecture for Irregular Networks (TRAIN)—a forwarding scheme based on a spanning tree that was extended to use some shortcut links.We propose its adaptation to Ethernet, using a new type of hierarchical Ethernet addresses and a procedure to assign them to bridges. We show that compared to RSTP, TRE offers improved throughput. The impact of transient loops in TRE is lower compared to the application of the classical shortest path routing protocols to Ethernet. Finally, TRE is self-configuring and its forwarding process is simpler and more efficient than in standard Ethernet and shortest path routing proposals.Publicad

Hierarchical Up/Down Routing Architecture for Ethernet backbones and campus networks

We describe a new layer two distributed and scalable routing architecture. It uses an automatic hierarchical node identifier assignment mechanism associated to the rapid spanning tree protocol. Enhanced up/down mechanisms are used to prohibit some turns at nodes to break cycles, instead of blocking links like the spannning tree protocol does. The protocol performance is similar or better than other turn prohibition algorithms recently proposed with lower complexity O(Nd) and better scalability. Simulations show that the fraction of prohibited turns over random networks is less than 0.2. The effect of root bridge election on the performance of the protocol is limited both in the random and regular networks studied. The use of hierarchical, tree-descriptive addresses simplifies the routing, and avoids the need of all nodes having a global knowleddge of the network topology. Routing frames through the hierarchical tree at very high speed is possible by progressive decoding of frame destination address, without routing tables or port address learning. Coexistence with standard bridges is achieved using combined devices: bridges that forward the frames having global destination MAC addresses as standard bridges and frames with local MAC frames with the proposed protocol.Publicad

Integración del dispositivo Stargazer en un robot social para la detección de marcas en el entorno

Este trabajo pretende solucionar el problema de deslocalización que sufren algunos robots por la acumulación de pequeños errores en su sensorización, mediante la instalación de un dispositivo capaz de identificar marcadores pasivos situados en el entorno, el Stargazer de la marca coreana Hagisonic. El objetivo final es conseguir integrar el dispositivo Stargazer en la navegación de un robot social, el Mbot, con el fin de desarrollar aplicaciones basadas en su uso que sirvan para mejorar el desplazamiento del robot. El desarrollo del código necesario en la integracion del dispositivo se ha llevado a cabo sobre el framework ROS (Robot Operating System). Para comprobar el correcto funcionamiento del dispositivo y sus aplicaciones se han llevado a cabo diversas pruebas tanto de precisión como de rendimiento.Ingeniería en Tecnologías Industriale

A Performance Comparison of Virtual Backbone Formation Algorithms for Wireless Mesh Networks

Currently wireless networks are dominant by star topology paradigm. Its natural the evolution is towards wireless mesh multi-hop networks. This article compares the performance of several algorithms for virtual backbone formation in ad hoc mesh networks both theoretically and through simulations. Firstly, an overview of the algorithms is given. Next, the results of the algorithm simulations made with the program Dominating Set Simulation Suite (DSSS) are described and interpreted. We have been extended the simulator to simulate the Mobile Backbone Network Topology Synthesis Algorithm. The results show that this algorithm has the best combination of performance characteristics among the compared algorithms

Toxicity Assessment of Sediments with Natural Anomalous Concentrations in Heavy Metals by the Use of Bioassay

The potential toxicity in riverbed sediments was assessed with a bioassay using the bioluminescent bacteria Vibrio fischeri. The selected area was characterized by the presence of ultramafic rocks (peridotites), and the sediments had high values in Ni, Cr, and Co. For the toxicity bioassay with Vibrio fischeri, water-soluble forms were used. The results indicated that most of the samples had a very low degree of toxicity, with 10% of reduction in luminescence in relation to the control; meanwhile 25% of the samples had a moderate degree of toxicity with a reduction in luminescence between 13 and 21% in relation to the control. The toxicity index correlated significantly with the concentrations of Ni and Cr in the water extracts. This toxicity bioassay was proved to be a sensitive and useful tool to detect potential toxicity in solutions, even with anomalous concentrations in heavy metals of natural origin

Implementing ARP-Path Low Latency Bridges in NetFPGA

The demo is focused on the implementation of ARP-Path (a.k.a. FastPath) bridges, a recently proposed concept for low latency bridges. ARP-Path Bridges rely on the race between broadcast ARP Request packets, to discover the minimum latency path to the destination host. Several implementations (in Omnet++, Linux, OpenFlow, NetFPGA) have shown that ARP-Path exhibits loop-freedom, does not block links, is fully transparent to hosts and neither needs a spanning tree protocol to prevent loops nor a link state protocol to obtain low latency paths. This demo compares our hardware implementation on NetFPGA to bridges running STP, showing that ARP-Path finds lower latency paths than STP

A Simple, Zero-configuration, Low Latency, Bridging Protocol

This paper describes a demo for a new type of bridges, ARP-Path bridges. These ARP-based Ethernet Switches rely on the race between ARP Request packets flooded over all links, to discover the minimum latency path to the destination host. The protocol uses all links, is loop free, uses the standard Ethernet frame format, is fully transparent to hosts and neither needs a spanning tree protocol to prevent loops nor a links state protocol to obtain minimum latency paths. Implementations in Linux and Openflow on NetFPGA show inherent robustness and fast reconfiguration. Simulation results show throughput and delay performance superior to the Spanning Tree Protocol and similar to shortest path routing, with lower complexity

A Simple, Zero-configuration, Low Latency, Bridging Protocol

This paper describes a demo for a new type of bridges, ARP-Path bridges. These ARP-based Ethernet Switches rely on the race between ARP Request packets flooded over all links, to discover the minimum latency path to the destination host. The protocol uses all links, is loop free, uses the standard Ethernet frame format, is fully transparent to hosts and neither needs a spanning tree protocol to prevent loops nor a links state protocol to obtain minimum latency paths. Implementations in Linux and Openflow on NetFPGA show inherent robustness and fast reconfiguration. Simulation results show throughput and delay performance superior to the Spanning Tree Protocol and similar to shortest path routing, with lower complexity.Comunidad de MadridJunta de Comunidades de Castilla-La Manch

HURP/HURBA: Zero-configuration hierarchical Up/Down routing and bridging architecture for Ethernet backbones and campus networks

Ethernet switched networks do not scale appropriately due to limitations inherent to the spanning tree protocol. Ethernet architectures based on routing over a virtual topology in which turns are prohibited offer improved performance over spanning tree, although in some cases suffer from excessive computational complexity. Up/Down routing is a turn prohibition algorithm with low computational complexity. In this paper we propose HURBA, a new layer-two architecture that improves Up/Down routing performance due to an optimization based on the use of hierarchical addressing, while preserving the computational complexity of Up/Down. The resulting architecture requires zero-configuration, uses the same frame format as Ethernet, allows upgrades by software update, and is compatible with 802.1D bridges by means of encapsulation. HURP protocol builds automatically a core with the interconnected HURP routing bridges and the standard bridges get connected to the edges in standard spanning trees. Simulations show that the performance of HURP, evaluated over various combinations of network topology and size, is close to the one of shortest path, is consistently better than that of Up/Down, and is equal or better than Turn Prohibition, with the advantage of having a lower complexity.En prens

All-Path Bridging: Path Exploration Protocols for Data Center and Campus Networks

Today, link-state routing protocols that compute multiple shortest paths predominate in data center and campus networks, where routing is performed either in layer three or in layer two using link-state routing protocols. But current proposals based on link-state routing do not adapt well to real time traffic variations and become very complex when attempting to balance the traffic load. We propose All-Path bridging, an evolution of the classical transparent bridging that forwards frames over shortest paths using the complete network topology, which overcomes the limitations of the spanning tree protocol. All-Path is a new frame routing paradigm based on the simultaneous exploration of all paths of the real network by a broadcast probe frame, instead of computing routes on the network graph. This paper presents All- Path switches and their differences with standard switches and describes ARP-Path protocol in detail, its path recovery mechanisms and compatibility with IEEE 802.1 standard bridges. ARP-Path is the first protocol variant of the All-Path protocol family. ARP-Path reuses the standard ARP Request and Reply packets to explore reactively the network and find the fastest path between two hosts. We compare its performance in terms of latency and load distribution with link-state shortest-path routing bridges, showing that ARP-Path distributes the load more evenly and provides lower latencies. Implementations on different platforms prove the robustness of the protocol. The conclusion is that All-Path bridging offer a simple, resilient and scalable alternative to path computation protocols