A Comment on "Beyond Fat-tree: Unidirectional Load-Balanced Multistage Interconnection Network"

A recent work proposed to simplify fat-trees with adaptive routing by means of a load-balancing deterministic routing algorithm. The resultant network has performance figures comparable to the more complex adaptive routing fat-trees when packets need to be delivered in order. In a second work by the same authors published in IEEE CAL, they propose to simplify the fat-tree to a unidirectional multistage interconnection network (UMIN), using the same load-balancing deterministic routing algorithm. They show that comparable performance figures are achieved with much lower network complexity. In this comment we show that the proposed load-balancing deterministic routing is in fact the routing scheme used by the butterfly network. Moreover we show that the properties of the simplified UMIN network proposed by them are intrinsic to the standard butterfly and other existing UMINs.     

多级互连网中的归约通讯

归约通讯作为聚合通讯中的一类，是实现数值计算、进程控制的重要手段，在并行处理中应用很广泛。由于归约通讯中有多个源结点主动地发送消息，因此它具有与ｍｕｌｔｉｃａｓｔ通讯迥然不同的行为特点。此文即在对归约通讯的行为特点和通讯过程的分析基础上，结合作者于［６］中提出的ＳＢＭＴ广播算法，提出了针对归约通讯的ＲＳＢＴ路由算法，并进一步作出了性能分析。     

The Multistage Cube: A Versatile Interconnection Network

The cube network can support both MIMD and SIMD processing in distributed systems. It allows flexible communications in systems like PASM, PUMPS, and the BMD test bed.     

Distributed Diagnosis in Multistage Interconnection Networks

Multistage interconnection networks (MINs) have been widely used in multiprocessor systems and high-speed networks, and the testing of MINs has been investigated by many researchers. However, in previous works the testing results are distributed among all processors, and all those results are needed to diagnose a network. This poses a problem for a truly distributed system where centralized control is not possible. In this paper, a distributed testing and diagnosis scheme for general MINs is discussed. By using the proposed method, concurrent testing and diagnosis of a network can be done by all processors independently, which neither interrupts the normal network operation nor needs any extra hardware.     

Multicasting in Generalized Multistage Interconnection Networks

Multistage interconnection networks (MIN) are popular in switching and communication applications. It is also well known as a hypercube derived architecture, offering a fixed-degree alternative to hypercube for a large class of applications. Message routing strategy in MIN is well known, however, multicasting issues for MIN has not been considered. This paper formulates the multicasting problem for MIN. We demonstrate that reordering the dimensions in MIN can lead to traffic reduced multicasting. This leads to the formulation of optimality criteria in MIN multicast operation. Traffic optimum multicasting in MIN is shown as a NP-Complete problem. We present a polynomial time greedy heuristic to generate traffic reduced multicast in MIN. The greedy approach generates a locally optimum solution. Analytical study and simulation results are presented showing the traffic reduction that can be obtained using our approach over traditional linearly ordered dimensions approach.     

Load-Balancing in Multistage Interconnection Networks under Multiple-Pass Routing

Multistage interconnection networks (MINs) have been widely used in multiprocessor systems, and recently they have been adopted as a way to construct ATM switches for broadband networks. In such systems, the fault-tolerant ability is an important issue. Many researchers have proposed ways to enhance the reliability of MINs, among them a low-cost and efficient way is to use multipass routing schemes in MINs in which thedynamic full access(DFA) property exists. The performance of multipass routing, however, has been largely ignored by researchers in the past. In this paper, we show that multipass routing may degrade the system performance if the communication loads are not well balanced among processors; congestion may appear in some processors and the useful communication bandwidth is badly affected. We propose methods to design DFA routing schemes that are load-balanced and thus can utilize system resources (i.e., the bandwidth) more efficiently.     

网间互联互通

网间互连互通就一直是公司密切关注的问题.随着交换机用户量的扩大,设备的数据种类也不断增多,如何做好通信畅通,提高用户的满意度,成为我们不懈追求的目标.文章主要对网间互连互通中的主要技术问题,如网间主叫号码传送、通信质量要求以及控制方式等进行讨论.     

A Kind of Multistage Interconnection Networks with Multiple Paths

1ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina,GralltNo.69473024.1IntroductionMultiprocessorsystemsoftenuseinterconnectionnetworkstoconnectproces-sorsormemorymodules-Atime-sharedbusisthesimplestformofinterconnectionnetworks,butitcannotprovidetheperformancerequiredinmultiprocessorsystemstoday.Acrossbarswitchnetworkisanalternativeusedintheearliersystemstoimplementinterconnection.Theonlydelaytoconnectinputstooutputsisthatofasingleswitchinggate,butacrossbarswitchnetworkisver…     

A Kind of Multistage Interconnection Networks with Multiple Paths

Mltistage Interconnection Networks(MINs)are orten used to provide interconnections in multiprocessor systems.A unique path MIN usually has lower hardware complexity and a simple control algorithm,but it lacks fault tolerance.This paper proposes a kind of multipat MINs,which are obtained by adding auxiliary links at the final stage in Quad Tree(QT) networks so that they can provide more paths between each source-destination pair,and presents their routing algorithm which is both destination tag based and adaptive.Starting with the routing tag for the minimum path between a given source-destination pair,the routing algorithm uses a set of rules to select switches and modify routing tag.In addition to trying the auxiliary link when link0 an link1 are unavilable,link1 will be tried when link0 ys unavailable.This feature distinguishing the proposed routing algorithm form that for QT networks makes better use of all the possible paths between the given source-destination pair.In the end,this paper introduces a performance index,which is called capacity,to compare different kinds of MINs .Comparison shows that the proposed MINs have better capacity than QT networks.     

论网络互连

网络互连是由重发器、网桥、路由器和网关的恰当使用和适当组合而实现的．这些中继设备具有不同的性能，因此，重要的是要选择最合适的互连设备．重发器互连类似的局域网段，形成单一扩展的局域网；网桥互连类似的LAN，形成单一的子网络；路由器互连子网络，形成单一网络，网关互连不同的网络，形成集成网络．     

互连网络拓扑等价的图分析法

提出了描述互连网络拓扑等价的图分析法。获得了全交叉网络与基准，逆基准，Ｏｍｅｇａ，ｆｌｉｐ，Ｓ＝Ｆ＝２ＳＷ榕树，简化数据变换等多级互连网络拓扑等价的逻辑名结构。阐明了用光学全交叉网络模拟实现上述网络的互连函数的原理及其多处理机，电信交换等领域的潜在应用。     

The Hyperstar Interconnection Network

In this paper, a multiprocessor interconnection topology, the hyperstar, based on the Cartesian product of star graphs is studied. The basic properties of the hyperstar are discussed and proved. This includes reduced degree and diameter, hierarchical structure, vertex symmetry, optimal routing, and shortest path characterization. The hyperstar is shown to be a member of the Cayley class of symmetric graphs. Embeddings of hypercubes, star graphs, and meshes are discussed. An optimal one-to-all broadcasting algorithm is obtained and analyzed. Some results on fault tolerance, parallel paths, Hamiltonian cycles, and VLSI layouts are obtained. Furthermore, a comparative study between the hyperstar and seven related networks is conducted. The comparison is based on scalability, broadcasting cost, link requirements, cost/performance ratio, and other static parameters such as degree, diameter, and average diameter.     

InfiniBand:一种新型的高速互连网络

随着计算能力向数据中心的集中,消除性能瓶颈和改进系统管理变得比以往更加重要。I/O子系统是造成这类问题的关键。InfiniBand被认为是可以消除当前I/O架构性能瓶颈的一种新的I/O技术。该文首先分析当前I/O系统的瓶颈问题,然后从IBA整体架构、层次结构、通信机制与VI架构、链路特性与服务质量等方面介绍了InfiniBand的具体情况,最后将Infiniband与其它一些高性能互连网络和标准进行了比较。     

Generating Systems of Equations for Performance Evaluation of Multistage Interconnection Networks

Multistage interconnection networks (Banyan networks) are frequently proposed as connections in multiprocessor systems, in ATM switches, or in Gigabit Ethernet switches. There exist several analytical models for evaluating the performance of such networks. Analytical models are much faster for this purpose than simulation. On the other hand, the development of an analytical model is very time-consuming. In this paper, we present a method for the automatic and fast generation of an analytical network model. The generated analysis handles networks of arbitrary size, arbitrary switching element sizes, arbitrary buffer lengths in each network stage, an arbitrary (but uniform) traffic pattern, and an arbitrarily chosen network load. The arbitrary traffic patterns include multicast traffic, which has not been considered by former models.     

Performance Analysis of Banyan-Type Multistage Interconnection Networks Under Nonuniform Traffic Pattern

Multistage Interconnection Networks(MINs) have a number of applications in the areas of computer and communications. The most widely researched structure among MINs is the (1)banyan type network. It has several variations such as buffered banyan, batcher-banyan, tandem banyan, recirculating banyan and banyan with contention resolution phase. Analytical performance evaluation is crucial for justifying the merit of the design in different operational conditions. While several analytical models have been proposed for the performance evaluation of MINs, they are mainly for uniform traffics. Even the models for nonuniform traffics have several shortcomings such as they only consider output buffered structure or do not consider blocking conditions.In this paper, the more accurate models than any other ones so far have been proposed for the performance evaluation of multibuffered banyan-type MINs under nonuniform traffic condition is obtained. The accuracy of proposed models are conformed by comparing with the results from simulation.Firstly, single buffer model is developed. Markov chain is used for the analysis. Multibuffer model is obtained from single buffer model. Simulation is performed using Discrete Evenet Simulaton(DES) method. As a results, proposed model proves to be very accurate.     

片上光网络:一种新型片上互连网络

随着单个芯片上集成的处理器的个数越来越多,传统的电互连网络已经无法满足对互连网络性能的需求,需要一种新的互连方式,因此光互连网络技术应运而生.目前,电互连的片上网络在功耗、性能、带宽、延迟等方面遇到了瓶颈,而光互连作为一种新的互连方式引用到片上网络具有低损耗、高吞吐率、低延迟等无可比拟的优势.本文主要探讨了片上光网络的...