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In recent years, vehicle networks require high bandwidth due to the increasing complexity of electronic control devices for vehicles due to the demand for advanced driving aids, infotainment and V2X communication. Therefore, Ethernet protocol was introduced and vehicle gateway system was newly introduced in vehicle system. The vehicle gateway system provides an interface for continuously connecting and exchanging vehicle data in different communication environments between the Controller Area Network (CAN) protocol and the Ethernet network protocol. There are two types of data exchange in the vehicle gateway. These are direct routing and indirect routing. Vehicle gateways are connected to external networks, which can lead to security vulnerabilities. So it needs security function to ensure message integrity. Recently, vehicle manufacturers have introduced gateway systems with security features that operate to verify the integrity of messages using cipher-based message authentication codes (CMAC). But applying security functions to a gateway system introduces delays in performing security functions. Therefore, in this paper, to design stable and efficient the vehicle gateway system with security function, we have tested and evaluated the latency time that can occur according to the routing methods which are direct routing and indirect routing. [ABSTRACT FROM AUTHOR]

The Ethernet switch is a primary building block for today's enterprise networks and data centers. As network technologies converge upon a single Ethernet fabric, there is ongoing pressure to improve the performance and efficiency of the switch while maintaining flexibility and a rich set of packet processing features. The OpenFlow architecture aims to provide flexibility and programmable packet processing to meet these converging needs. Of the many ways to create an OpenFlow switch, a popular choice is to make heavy use of ternary content addressable memories (TCAMs). Unfortunately, TCAMs can consume a considerable amount of power and, when used to match flows in an OpenFlow switch, put a bound on switch latency. In this paper, we propose enhancing an OpenFlow Ethernet switch with per-port packet prediction circuitry in order to simultaneously reduce latency and power consumption without sacrificing rich policy-based forwarding enabled by the OpenFlow architecture. Packet prediction exploits the temporal locality in network communications to predict the flow classification of incoming packets. When predictions are correct, latency can be reduced, and significant power savings can be achieved from bypassing the full lookup process. Simulation studies using actual network traces indicate that correct prediction rates of 97% are achievable using only a small amount of prediction circuitry per port. These studies also show that prediction circuitry can help reduce the power consumed by a lookup process that includes a TCAM by 92% and simultaneously reduce the latency of a cut-through switch by 66%. [ABSTRACT FROM AUTHOR]

Conventional Ethernet protocols struggle to meet the scalability and performance requirements of data centers. Viable replacements have been proposed for data center ethernet (DCE): link-layer Multipathing (MP) is deployed to replace spanning tree protocol (STP) and thus improve network throughput; end-to-end link-layer congestion control (CC) is proposed to better guarantee loss-free frame delivery for Ethernet. However, little work has been done to incorporate MP and CC to offer a more comprehensive solution for DCE. In this paper, we propose a two-tier solution by integrating our dynamic load balancing Multipath (DLBMP) scheme with CC. Instead of using two separate parameters, i.e., path load and buffer level, to trigger MP and CC, our solution only needs to monitor path load metric to manage MP and CC in an integrated way. Different from a single CC mechanism, which generates congestion notifications from network core, our integrated CC can make use of link load information in access switches which directly inform sources to control their traffic admission. To minimize overhead and accelerate update, SDN techniques are employed in our implementation, which decouples routing intelligence from data transmission. Hence, data sources can react more rapidly to congestion and network can be guaranteed with loss-free delivery. In addition, our MP scheme is further improved by introducing application-layer flow differentiation. With such a fine flow differentiation (FFD) mechanism, traffic can be more evenly distributed along multipaths, resulting in better bandwidth utilization. Simulation results show that our combined solution can further improve network throughput with FFD mechanism and guarantee loss-free delivery with integrated CC. [ABSTRACT FROM PUBLISHER]

Amongst link technologies, InfiniBand has gained wide acceptance in the framework of High Performance Computing (HPC), due to its high bandwidth and in particular to its low latency. Since InfiniBand is very flexible, supporting several kinds of messages, it is suitable, in principle, not only for HPC, but also for the data acquisition systems of High Energy Physics (HEP) Experiments. [ABSTRACT FROM PUBLISHER]

The foundation of a research project about a model of computer networks with media access control mechanism based on the IEEE standard 802.3-2005 is presented. The model draws from the theory of self-similar sets for establishing the impact level that the long-range-dependent temporary correlations have on the performance of such networks. A new method for the estimation of self-similar levels based on a variation of the Whittle estimator is postulated. [ABSTRACT FROM AUTHOR]

Overlapping computation with communication is a key technique to conceal the effect of communication latency on the performance of parallel applications. Message Passing Interface (MPI) is a widely used message passing standard for high performance computing. One of the most important factors in achieving a good level of overlap is the MPI ability to make progress on outstanding communication operations. In this paper, we propose a novel speculative MPI Rendezvous protocol that uses RDMA Read and RDMA Write to effectively improve communication progress and consequently the overlap ability. Performance results based on a modified MPICH2 implementation over 10-Gigabit iWARP Ethernet reveal a significant (80–100%) improvement in receiver side overlap and progress ability. We have also observed up to 30% improvement in application wait time for some NPB applications as well as the RADIX application. For applications that do not benefit from this protocol, an adaptation mechanism is used to stop the speculation to effectively reduce the protocol overhead. [ABSTRACT FROM AUTHOR]

As Ethernet traffic increases rapidly in carrier networks, service providers have an increasing need for Ethernet infrastructure networking in order to scale their Ethernet services. Ethernet infrastructure transports Ethernet traffic over distance, protects the traffic from link and nodal failures, and aggregates Ethernet connections from a large number of low-speed ports onto a much smaller number of high-speed ports. An Ethernet infrastructure allows service providers to inexpensively interconnect end user locations with one another for private line services, and to interconnect end users with the VPLS and IP/MPLS service edges for enterprise, residential, and mobility services. OAM and protection capabilities are critical to enable Ethernet to be deployed as an infrastructure technology. This article reviews several important developments in Ethernet OAM and protection standards, and discusses how those capabilities are vital for the creation of an effective Ethernet infrastructure. [ABSTRACT FROM AUTHOR]

In this article, a novel network architecture called resilient burst ring is proposed to implement the next-generation WDM-supported ultrahigh-speed (100 gigabit or higher) carrier Ethernet. This architecture inherits all the best features of resilient packet ring (IEEE 802.17), provides a burst-mode data transmission scheme through a two-sublayer (optical and electronic) hierarchy, and realizes the WDM-supported ultra-high-speed Ethernet with scalability and reliability. RBR adopts a two-layer buffering scheme to resolve the contentions of optical burst packets and provides three different data transmission modes. With the proposed PriorityOnly-Destination-Delay resource reservation control protocol, RBR can provide a flexible Q0S strategy to implement the transmission of all of the applications and services in existing networks. [ABSTRACT FROM AUTHOR]

In variable-speed electrical drives, data transmission between an electric motor and an inverter is required because of sensors installed at the motor. Sensor information is used both in the motor control and in the diagnostics. For example, a data transmission medium can be implemented either by additional cabling or through the power cable. However, additional cabling is neither a cost-effective nor even a reliable solution. Previously, only a few application-specific solutions for data transmission via power cables have been presented. A general method to implement a broadband and Ethernet-based communication medium between a motor and an inverter is proposed here. The method forms an Ethernet-supported packet-based communication medium over the motor power cable. Ethernet supports all kind of protocols implemented above the link layer. The channel and noise characteristics are described. According to these, a coupling interface is developed that allows installing the communication device safely to a three-phase inverter-fed motor power cable. A channel capacity analysis is also performed. Laboratory measurements are carried out and analysed with the proposed method, and two possible applications are discussed. [ABSTRACT FROM AUTHOR]

Fibre-to-the-home (FTTH) is recognised as the choice for true broadband access, and major implementations of the technology are beginning to arrive. The main drivers of FTTH are bandwidth-demanding applications. Among various architectures and technologies of FTTH, home run active Ethernet FTTH is an interesting technology. The main design issue related to FTTH deployments, however, is the high level of CAPEX. In order to justify FTTH deployments, service providers and network planners require a tool to assist them in selecting an optimised deployment strategy and network design. The lack of modelling tools to perform high-level FTTH network planning is the main motivation behind this paper. This work presents the result of a study based on a configurable and customisable techno-economic model, which helps network planners and decision makers to have a high-level picture of Ethernet FTTH deployment. The model captures both the technical and economic aspects of the Ethernet FTTH networks and provides key business performance indicators. The results of a case study for an Ethernet FTTH deployment in a capital city are presented. [ABSTRACT FROM AUTHOR]

Abstract: Real-time control applications will benefit in the near future from the enhanced performance provided by multi-core processor architectures. Nevertheless real-time communication will continue to be critical in distributed plasma control systems where the plant under control typically is distributed over a wide area. At RFX-mod real-time communication is crucial for hard real-time plasma control, due to the distributed architecture of the system, which consists of several VMEbus stations. The system runs under VxWorks and uses Gigabit Ethernet for sub-millisecond real-time communication. To optimize communication in the system, a set of detailed measurements has been carried out on the target platforms (Motorola MVME5100 and MVME5500) using either the VxWorks User Datagram Protocol (UDP) stack or raw communication based on the data link layer. Measurements have been carried out also under Linux, using its UDP stack or, in alternative, RTnet, an open source hard real-time network protocol stack. RTnet runs under Xenomai or RTAI, two popular real-time extensions based on the Linux kernel. The paper reports on the measurements carried out and compares the results, showing that the performance obtained by using open source code is suitable for sub-millisecond real-time communication in plasma control. [Copyright &y& Elsevier]

ISO-16484-5 (EN ISO 2003) and ANSI/ASHRAE Standard 135-2004 (BACnet®) is a standard data communication protocol for building automation and control systems. In this study, the performance of three BACnet local area networking options is investigated with simulation models developed using ARENA, a tool for simulating discrete event dynamic systems. This study evaluates the delay characteristics of Master-Slave/Token-Passing (MS/TP), ANSI/ATA-878. 1 (ARC- NET), and ISO-8802-3 (Ethernet) medium access control (MAC) layers being used to deliver BACnet application services. Analysis of the simulation results was used to develop recommendations that should be considered when designing and operating BACnet systems. [ABSTRACT FROM AUTHOR]

Enterprises are increasingly using Ethernet as the foundation for transforming their networks to Internet Protocol. Simultaneously, service providers are deploying Ethernet to exploit the demand for wide-area Ethernet services and as the infrastructure for new residential services. such as IPTV. This is due to Ethernet's low cost per bit and ubiquity in local area networks. Recent years have seen the widespread deployment of IP/MPLS networks to address this opportunity. IP/MPLS enables enhanced flexibility over the same converged network for IP and legacy services, avoiding the need to build separate per-service networks. It also adds carrier-grade capabilities such as quality of service, traffic engineering, and resiliency, thereby enabling new multipoint services such as virtual private LAN service. However, using Ethernet for "always-on" and other mission-critical services has resulted in new resiliency requirements, in both the access and the network core. Two novel developments address these high expectations by enabling significant improvements in service availability. These are pseudowire redundancy and Ethernet multi-chassis link aggregation. This article reviews the current redundancy mechanisms typically deployed in Ethernet and MPLS networks. We show how additional enhancements are required in both the network core and the access to the Ethernet service. We describe new pseudowire redundancy and MC-LAG mechanisms, showing how they work together to enable end-to-end protection for Ethernet virtual private wire services and VPLS. [ABSTRACT FROM AUTHOR]

The article offers information on the proposed quality of service differentiation scheme for the Institute of Electrical and Electronics Engineers (IEEE) 802.16 wireless mesh networks. According to the article, WMN is becoming an important architecture of future generations of wireless communications systems wherein the quality of service provisioning provides an essential role in optimizing its performance. It provides a detailed discussion on the system model, frame structure, different scheduling schemes and collocated topology. It also discusses the different relevant issues and potential performances associated with the approach.

In 1995, the IEEE approved the 802.12 standard for data transmission at 100-Mbit/s using the Demand Priority Net- work Access protocol. 100VG-AnyLAN products conforming to this standard offered an upgrade path for Ethernet and Token Ring networks, without requiring new building wiring. A key factor in the approval of the 802.12 standard was the demonstrated error detection properties of its coding scheme. In particular, the coding scheme allows the detection of error bursts affecting encoded data carried on four parallel conductors, using nothing more than the standard IEEE 32-bit cyclic redundancy check applied to the unencoded data. Although these error detection properties were presented for verification as part of the standards process, for many years commercial considerations prevented public disclosure of how the code was actually found. These considerations no longer apply, and, in this paper, we explain in detail the design principles of the code, combining geometrical insight, linear algebra, combinatorial reasoning, and computer search. [ABSTRACT FROM AUTHOR]

Abstract: Bandwidth demands on ubiquitous Ethernet have grown immensely, driven by the rapid expansion of real-time applications like audio/video streaming. In a related research, the authors designed a novel high-performance custom network processor chip using field programmable gate arrays (FPGAs). The main function of this chip (named SPEED) is to bypass the operating system processing of network protocol stack at the host computer by off-loading its networking functions to hardware. This simplification is not only required to fit in a hardware solution, but also it improves network performance. The novel chip utilizes the concept of Ethernet channels, where Ethernet frames are addressed in a multicast addressing scheme. In this article, we integrate the chip with a Firewire peripheral interface (FPI). A crucial function of the FPI design is to convert the IEEE 1394 isochronous traffic to the Ethernet frame format via two independent asynchronous write and read buffers. The FPI also manages the SPEED hardware interrupt signals in a bi-directional communication scheme. The goal of this research is to map isochronous Firewire packets into Ethernet frames by utilizing the SPEED Ethernet channel assignment capability. We used Verilog Hardware Description Language (HDL) to synthesize the FPI design. Since the FPI needs to support bi-directional communication, we also present a generic HDL model for bi-directional data sharing, which can be used in similar bi-directional applications. Initial performance measures show that the FPI consumes less that 0.15W of power. Also we found that the synthesized design utilizes only 28% of the target chip resources. Hence it was possible to incorporate it with the SPEED design in the same FPGA chip. This low power consumption will lead to powering SPEED-FPI based network devices through the network cable and eliminate the process of regular electrical power outlet installations and maintenance. Thus, the SPEED-FPI system reduces the installation complexity, especially for large number of devices (e.g., surveillance cameras). [Copyright &y& Elsevier]

The 3GPP specifies the IP multimedia subsystem (IMS) to provide several kinds of multimedia services in UMTS Release 5 and later releases. Interworking at the service layer between 3GPP and Wimax networks requires interworking between IMS functionality. By studying several interconnection scenarios and the main functionality of IMS, this article analyzes how the interworking of 3GPP and Wimax networks can be performed to support different levels of service interconnection. Special attention is paid to the interconnection at the session negotiation level, using SIP (the base protocol of the IMS), COPS/Go, and Diameter protocols/interface to provide session negotiation with QoS and AAA (authentication authorization accounting) support. [ABSTRACT FROM AUTHOR]

We propose an extension of the classical CSMA/CD protocol that eliminates its three main drawbacks. The new protocol, called dual-mode CSMA/CD (CSMA/DM), operates in two modes, light mode and heavy mode. The light mode of CSMA/DM is almost the same as the original CSMA/CD protocol and is primarily used when the LAN load is light. The heavy mode is a collision free mode and is applied when the LAN load is heavy. The proposed modification to CSMA/CD is minimal while performance gain is significant. CSMA/DM automatically switches between its two modes based on the observed LAN load. Under heavy mode, the monitor station in a CSMA/DM LAN allocates bandwidth to those busy stations without collisions. The newly added priority scheme in the heavy mode allows stations to reserve bandwidth for their high priority frames. Compared with the current collision-free fast Ethernet and Gigabit Ethernet, CSMA/DM has the advantage of not needing any extra switches or hubs while maintaining comparable performance. Its priority scheme provides more flexibility on bandwidth distribution than in fast Ethernet and Gigabit Ethernet. It can also be easily adapted for high-speed wireless LANs. More importantly, CSMA/DM should be a good alternative of the widely used CSMA/CA (collision avoidance) in mobile ad hoc networks (MANET) and sensor networks. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In Mobile IP networks, the home agent manages the destination information of all mobile terminals. It receives as proxy the packets destined for the mobile terminal and transfers them to the new location of the terminal. When the number of terminals in the network is increased, the home agent must manage a large amount of information, which increases the retrieval processing load in packet transfer. It is possible that a packet may be lost by an overloaded home agent. This paper proposes a method of eliminating the retrieval processing of the home agent in packet transfer by utilizing ARP, and of reducing the load of the whole packet transfer process. It is shown experimentally that even if sufficient mobile terminal entries to completely fill the location information list for 200,000 entries are registered, the home agent can transfer all packets without any packet loss in Fast Ethernet. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(6): 32–40, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20249 [ABSTRACT FROM AUTHOR]

The article discusses the result of a study concerning the performance of the 10-Gigabyte Ethernet, a technology developed to reduce the performance gap between Ethernet-Ethernot networks. Ethernot uses hardware-offloaded protocol stacks and feature-rich interfaces that are exposed to end-host applications. Myricom has introduced network adapters which uses Myrinet interconnect technology with an Ethernet underlying wire protocol. The technology has Chelsio T110 TCI-IP-based network adapter that uses a Fujitsu XG800 virtual cut-through switches.

Abstract: Nowadays, Ethernet networks may be profitably employed also at the lowest levels of factory automation systems. Indeed, suitable application layer protocols for Ethernet have been recently developed in order to cope with the critical requirements imposed by the industrial applications. In this paper we focus on the protocols used by PROFINET, an emerging standard for industrial communications based on Ethernet, which is now available in two different versions, named CBA and IO. After a description of the protocols, we show the results of some tests aimed at evaluating the performances of such a network. In particular, we concentrate the attention on the times necessary to transfer limited amounts of data among stations. With regard to PROFINET CBA, the outcomes of an experimental set-up comprising several components, show, for the transfer times, highly variable values, dependent on the network load. Conversely, for PROFINET IO, the results of a set of numerical simulations we performed, allow to expect constant transfer times of some milliseconds, or even less, provided that an accurate time synchronization between stations is maintained. [Copyright &y& Elsevier]

An event builder based on communication networks has been used in high-energy physics experiments, and various networks have been adopted, for example, IEEE 802.3 (Ethernet), asynchronous transfer mode (ATM), and so on. In particular, Ethernet is widely used because its infrastructure is very cost effective. Many systems adopt standard protocols that are designed for a general network. However, in the case of an event builder, the communication pattern between stations is different from that in a general network. The unique communication pattern causes congestion, and thus makes it difficulty to quantitatively design the network. To solve this problem, we have developed a simple network protocol for a data acquisition (DAQ) system. The protocol is designed to keep the sequence of senders so that no congestion occurs. We implemented the protocol on a small hardware component La field programmable gate array (FPGA)] and measured the performance, so that it will be ready for a generic DAQ system. [ABSTRACT FROM AUTHOR]

Focuses on the evolution of communication methods used in industrial application; Description of the benefits that CAN offers for industries; Advantages of using TCP/IP over Ethernet; Development of industrial-grade connectors and cabling for Ethernet.

The boundaries between packet and circuit networks have long disappeared, with many traditional circuit-switched applications such as voice and video now being carried over packet-switched IP/MPLS or Ethernet networks. However, this transition has happened so fast that many OAM functions supported by circuit-switched networks such as SONET/SDH are still unmatched in packet networks. In order to match the quality sustained by circuit-switched networks, OAM functions must also be developed for such packet networks. A number of recent efforts have started to address OAM functions for IP/MPLS and Ethernet packet technologies. Service providers and carriers alike are the driving force behind the work, as there is general recognition that to generate sustained revenues, services must be efficiently managed. In this article we discuss issues in providing OAM features and capabilities for MPLS-based packet networks. [ABSTRACT FROM AUTHOR]

Using the upgrading of the measuring system of the GOL-3 plasma facility as an example, the structure of hardware and software environment developed for data-acquisition systems of large pulse electrophysical plants is considered. The equipment is built into 3U-size 19-inch subracks. The control computers are connected to the measuring equipment via standard network facilities (Ethernet-10/100 interface and TCP/IP protocol). At present, we have begun making basic diagnostic measurements using the ADC1250/32 multichannel synchronous data-acquisition systems. [ABSTRACT FROM AUTHOR]

When bulk data is transferred between end hosts over an IP network, a known problem is the limited throughput obtained at the application level due to the memory copy processing load between the kernel buffer and the user buffer depending on the operating system. To solve this problem, in this paper we propose a high-speed bulk data transfer architecture called Network Direct Memory Access (Network DMA) and describe its design, implementation, and test results. The purpose of Network DMA is to be a transport function installed on a network interface card (NIC) and to achieve high-speed and reliable data transfers over a network between the user buffers of the end hosts without requiring operating system-specific processing. An application will use the data transfer function provided by a new interface capable of directly specifying the send destination host and the target transfer buffer. Based on the proposed architecture, we developed a 622-Mbit/s ATM NIC and Gigabit Ethernet NIC incorporating the Network DMA. The ATM NIC we developed achieved a continuous transfer throughput of 540 Mbit/s (99% bandwidth usage efficiency at the application level) in data transfer tests between general-purpose PCs. The Gigabit Ethernet NIC achieved an 800 Mbit/s continuous transfer throughput. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(11): 57–65, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10107 [ABSTRACT FROM AUTHOR]

The shared media local area networks (LAN) such as Ethernet/FDDI has the bottleneck of bandwidth scalability. ATMLAN based on asynchronous transfer mode (ATM) switch is considered interesting at present as the next-generation multimedia LAN to dissolve this bottleneck. The research and development of ATM has mostly been promoted for application to the public network. With respect to LAN, a new investigation is needed which includes the architecture since there are various requirements such as compatibility to the existing protocol, the simplification of the network control, and the drastic reduction of the system cost. This paper proposes the ATM-oriented multimedia LAN (ATOMLAN) architecture which meets the forementioned requirements. The proposed architecture has the following three features: (I) the ATMLAN addressing, considering the affinity to the existing protocol and the efficient internetworking; (2) the high-speed connection control to realize a high throughput for the connectionless-type data transfer; and (3) the simple and efficient traffic control for the high-speed burst-multimedia service. Using the proposed architecture, a seamless high-speed multimedia network can be realized, from the desk-top to the broadband network. [ABSTRACT FROM AUTHOR]

Computing systems are evolving into very large global networks that interconnect competing individuals, organizations, and even countries. We present a secure network protocol called Authenticated Datagram Protocol (ADP) that optimizes performance by establishing host-to-host secure channels and building agent-to-agent channels on top of host-to-host channels. However, the performance advantages of ADP come with an accompanying set of trust requirements that are noticeably stringent for a network spanning mutually distrustful organizations. We identify the cause for this stringency to be propagation of trust relationships in ADP and present methods to break their propagation, thereby accomplishing a significant reduction in ADP's trust requirements. ADP, being a protocol for establishing host- to-host channels, can be handled at the subtransport level of the protocol hierarchy. A prototype of ADP has been implemented on Sun workstations connected by an Ethernet. Experimental measurements confirm that both the average latency of messages and the maximum throughput are substantially better than other secure protocols. [ABSTRACT FROM AUTHOR]

Communication protocols provide facilities that may be used by processes to intercommunicate across machine boundaries. In this context, performance evaluations serve as guidelines to provide efficient behavior for distributed applications as characterized by critical transfer time constraints. Since data transfers in actual operating environments are carried out on preexistent intermachine communications, the effect of loaded communication media on performance is of interest. This paper presents a study on the performance achieved in the presence of variable background load when applications are directly based on the transport level. The analysis was carried out through experiments over an Ethernet local area network and was repeated on two different protocol suites, TCP/IP and XNS. Communications by means of datagram and reliable transfer primitives were analyzed for both protocol structures. The dependency of protocol performance on background load, as well as the localization of the most important causes affecting throughput as load increases, were assessed. Different strategies to reduce the impact of background load are proposed on the basis of the results acquired so far. [ABSTRACT FROM AUTHOR]

We propose a MAC-level protocol with bounded packet delay time for Ethernet-type networks. The proposed protocol, named Virtual Token, aims at improving the performance of CSMA/CD under heavy load, retaining its good characteristics for light and moderate traffic conditions. The improvement is achieved by passing an implicit token. Collision-free protocols based on passing explicit tokens are known to perform well under heavy traffic conditions, but they are outperformed by collision protocols for lighter loads. Unfortunately, the maximum packet delay in pure collision protocols is not bounded which is unacceptable in certain applications. We prove that the Virtual Token protocol guarantees packet delivery in a bounded time, and report results of numerous simulation experiments carried out to investigate its performance. [ABSTRACT FROM AUTHOR]

We introduce an improved Ethernet ring protection method, selective filtering database (FDB) advertisement, to minimize traffic overshoot in the event of a failure or recovery. On the protection switching event, the proposed method makes all ring nodes perform an FDB flush except the FDB entries associated with their client subnets. Then, ring nodes rapidly exchange their client MAC address lists so that their FDBs are immediately updated by indirect MAC address learning. The proposed scheme guarantees fast and reliable protection switching over the standard scheme. [ABSTRACT FROM AUTHOR]

There is increasing pressure on manufacturers in all sectors of industry to improve processes, reduce costs and boost productivity. Ethernet technology has been hailed as the key to achieving all these goals, and to boosting companies' competitiveness on increasingly aggressive global markets. The move to Industrial Ethernet has been rapid across all sectors of industry, and represents a step change from the standardisation on the various open and proprietary fieldbus protocols that was seen during the 1990s. Industrial Ethernet, in essence, is the use of Ethernet as the data link layer protocol in the OSI seven-layer model, with a fieldbus protocol as the application layer. This is conceptually similar to the various fieldbus options that are actually the use of RS232/485 as the data link layer, with the fieldbus protocol itself at the application layer. [ABSTRACT FROM AUTHOR]