Performance analysis of multistage interconnection networks using a multicast algorithm

Performance analysis of multistage interconnection networks with redundant links

In this paper, we study multicasting in the self-routing multistage interconnection networks (MINs) for asynchronous transfer mode (ATM) switch architectures. Many B-ISDN applications require multicast connections in addition to conventional point-to-point connections. This paper presents a novel approach to support multicast connection, on the basis of a restricted address encoding scheme which constructs a short fixed-size multicast header and a recursive scheme that recycles a multicast packet one or more times through the network to send it to the desired destinations. The proposed two-phase multicast algorithm provides deadlock-free multiple multicast connections in MIN-based ATM switches. The emphasis is on analyzing the performance of an unbuffered MIN-based switch using the multicast algorithm in terms of network throughput. The proposed algorithm can be easily applied to buffered MIN-based ATM switches.

Proposes an analysis technique for a class of Multistage Interconnection Networks (MIN's) that have finite buffers at their switch inputs and operate in a synchronous packet-switched mode. The authors examine the issue of clock period in design and analysis of synchronous MIN's and propose a model based on small clock periods. Then they analyze their "small cycle" design and compare the results with those obtained from the standard "big cycle" model that is currently used. The significant performance improvement of their model is shown based on various clock width, data width, and buffer length.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

This paper addresses the problem of efficient multicast communication in wavelength-division multiplexed optical networks. In particular, we consider all-optical networks in which each transmitting node may deliver its message to some fixed number of destination nodes on a light path. The number of destination nodes that may receive the message using a single path depends on the power budget of the transmitting node. We study the wavelength requirements for multicast communication under this model.

A generalized architecture is presented for reconfigurable m-ary tree structures, where m is any integer >1. The approach is based on a generalized multistage interconnection network (MIN), which is a generalization of the augmented shuffle-exchange MIN introduce by the authors previously (1990) for obtaining reconfigurable binary tree structures. The generalized architecture with m/sup k/ processing elements or nodes (where k is any integer >1) is implemented with a k-stage MIN. A single control code issued to the MIN establishes a distinct m-ary tree configuration among the nodes. The favorable features of the architecture include fast reconfiguration, simplified hardware in the nodes and the MIN, and simple routing control. The reconfigurability of the architecture is proved, and the results of the analysis are utilized to provide a procedure to synthesize the m-ary tree configuration that is generated for any given control code. Considerations for implementing the switching elements of the MIN are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

We present a queueing model for performance analysis of finite-buffered multistage interconnection networks. The proposed model captures network behaviour in an asynchronous communication mode and is based on realistic assumptions. A uniform traffic model is developed first and then extended to capture nonuniform traffic in the presence of a hot-spot. Throughput and delay are computed using the proposed model and the results are validated via simulation. The analysis is extended to predict performance of MIN-based multiprocessors. The effects of buffer length, switch size, and the maximum allowable outstanding requests on the system performance are discussed. Various design decisions using this model are drawn with respect to delay, throughput, and system power.

The efficient and high throughput multicast communication in interconnection networks is known as a fundamental but hard problem. In the literature, most of the related works handle multicast communication within limited operating conditions and low throughput. Recently, a new multicast scheme, known as qualified groups QG, was proposed in [2] and has shown promising performance characteristics. However, this scheme has been examined only, so far, under deterministic routing and symmetric networks. In order to examine the QG in more realistic and different scenarios, this paper makes two major contributions. Firstly, the QG is generalised here to handling multicast communication in symmetric, asymmetric and different network sizes. Secondly, unlike most existing multicast algorithms the present study proposes a new adaptive multicast algorithm that maintains good performance levels for various system sizes. Our experiments show that the QG exhibits significant improvement in both throughput and multicast latency.

The wireless mesh network is an emerging technology that provides high quality service to end users as the "last milerdquo of the Internet. Furthermore, multicast communication is a key technology for wireless mesh networks. Multicast provides efficient data distribution among a group of nodes. However, unlike other wireless networks, such as sensor networks and MANETs, where multicast algorithms are designed to be energy efficient and to achieve optimal route discovery among mobile nodes, wireless mesh networks need to maximize throughput. This paper proposes two multicast algorithms: the level channel assignment (LCA) algorithm and the multichannel multicast (MCM) to improve the throughput for multichannel and multi-interface mesh networks. The algorithms build efficient multicast trees by minimizing the number of relay nodes and total hop count distances of the trees. The algorithms use dedicated channel assignment strategies to reduce the interference to improve the network capacity. We also demonstrate that using partially overlapping channels can further diminish the interference. Furthermore, additional interfaces help to increase the bandwidth, and multiple gateways can further shorten the total hop count distance. Simulations show that those algorithms greatly outperform the single-channel multicast algorithm. We also observe that MCM achieves better throughput and shorter delay while LCA can be realized in distributed manner.

Because low Earth orbit (LEO) satellites provide short round-trip delay, they are becoming increasingly important for providing real-time applications such as voice and video traffic to global coverage. Multicast communication that simultaneously transmits messages from a source to a group of destination is essential for future LEO satellite networks. The multicast routing problem in terrestrial networks has already been studied extensively in the past. In LEO networks, previous research on the multicast routing only considers the network cost optimization without satisfying the delay requirement. This paper proposes a distributed multicast tree algorithm with sub-optimal network cost under the delay bound in LEO satellite networks. We compare the performance of our MC algorithm when applied to the LEO satellite networks with the periodically time-variant ISL sub-network. The algorithms are judged based on the quality of MC trees it generates and its efficiency in managing the network resources. Simulation results show that our delay-constrained multicast algorithms are capable of fulfilling the delay requirements in LEO satellite networks.

Current MultiProcessor System-on-Chips exploit the Network-on-Chip (NoC) design paradigm as a viable solution to get an efficient and scalable communication backbone. As the number of integrated cores keeps growing, alternatives to the multi-hop nature of NoCs like Wireless Networks-on-Chip (WiNoCs) have been proposed to provide a subset of network nodes with a wireless interface that enables long-range communications in a single hop. In this work, we propose the use of on-chip wireless communication on Multi-stage Interconnection Networks (MINs) based NoCs. After extending the well-known Noxim platform to support Wireless MINs architectures, we perform an extensive set of cycle-level estimation demonstrating that, while traditionally used in high-performance parallel computing, wireless-augmented MINs represent a very promising candidate for the applicability of on-chip radio communications technologies, with a noticeable improvement in both average delay and saturation point, at the cost of an estimated energy overhead ranging from \(2.8\%\) up to \(18.4\%\) in the case of 128 core nodes.

Summary form only given. Multicast communication, which involves transmitting information from one node to multiple nodes, is a vital operation in both broadband integrated services digital networks (BISDN) and scalable parallel computers. Among different multicast switching networks, much work has been centered around the crossbar switches due to the simplicity of implementation. However, crossbars have the maximum number of crosspoints and implementation complexity among all switching fabrics. Multistage interconnect networks (MINs) such as Clos networks have attracted many attentions in recent years due to the nonblocking property as the crossbars, while at the same time possessing many advantages over crossbars. However, no multicast scheduling and routing algorithm have been applied to Clos network. This paper explores this aspect - we study some existing multicast scheduling and routing algorithms and apply them to Clos networks. Moreover, we propose two packet scheduling strategies to improve the system performance in terms of switch blocking probability and throughput, as shown by simulations.

Across many architectures and parallel programming paradigms, collective communication plays a key role in performance and correctness. Hardware support is necessary to prevent important collective communication from becoming a system bottleneck. Support for multicast communication in Networks-on-Chip (NoCs) has achieved substantial throughput improvements and power savings. In this paper, we explore support for reduction or many-to-one communication operations. As a case study, we focus on acknowledgement messages (ACK) that must be collected in a directory protocol before a cache line may be upgraded to or installed in the modified state. This paper makes two primary contributions: an efficient framework to support the reduction of ACK packets and a novel Balanced, Adaptive Multicast (BAM) routing algorithm. The proposed message combination framework complements several multicast algorithms. By combining ACK packets during transmission, this framework not only reduces packet latency by 14.1% for low-to-medium network loads, but also improves the network saturation throughput by 9.6% with little overhead. The balanced buffer resource configuration of BAM improves the saturation throughput by an additional 13.8%. For the PARSEC benchmarks, our design offers an average speedup of 12.7% and a maximal speedup of 16.8%.

Multistage interconnection networks are used as a medium for interconnecting processors and memories in multiprocessor systems. Multistage interconnection networks are an effective substitute for crossbar switches, used in telephone network systems and parallel computers, due to their low cost, better performance and easy maintainability. In this paper, we propose new fault-tolerant hybrid multistage interconnection networks obtained from shuffle exchange gamma interconnection network (SEGIN) and logical neighborhood network named as shuffle exchange gamma logical neighborhood interconnection network (SEGLNIN). We evaluated the performance of SEGLNIN in terms of disjoint paths, reliability and hardware cost and compared it with some well-known MINs like shuffle exchange network (SEN), shuffle exchange network with one extra stage (SEN +) and shuffle exchange network with two extra stages (SEN + 2), SEGIN-1, and SEGIN-2. The results illustrate that the performance of the proposed SEGLNIN is better than that of the compared networks in terms of reliability and disjoint paths.

The deployment of real-time and multimedia applications over Wireless LAN has gained a growing interest in this last decade. These applications, e.g. video streaming, require tight guarantee on Quality of Service (QoS). Also, they use multicast communication in order to reduce the bandwidth consumption. However, in WLAN, multicast packets are sent with the basic rate (lowest rate); which results in capacity wasting because of longer channel occupancy. Moreover the lack of feedback mechanism makes it difficult to deal with reliability or service quality. In this paper, we propose to rely on the WLAN multi-rate capability, in order to transmit multicast packets with higher and dynamic rate than the basic rate. Unlike other existing protocols that use a static-threshold to decide when to change transmission rate, we propose a novel dynamic rate-adaptation mechanism based on Quality of Experience (QoE), namely Q-DRAM. According to the clients' feedback on QoE, we adapt the multicast rate: (i) when users had bad QoE we reduce the multicast transmission rate; (ii) when users had good QoE, we increase the multicast transmission rate. Simulation results show that Q-DRAM increases the wireless channel utilization and maximizes users' QoE, compared to existing solutions as well as to the IEEE 802.11 standard.

Efficient routing of messages is a key to the performance of multicomputers. Multicast communication refers to the delivery of the same message from a source node to an arbitrary number of destination nodes. While multicast communication is highly demanded in many applications, most of the existing multicomputers do not directly support this service; rather it is indirectly supported by multiple one-to-one or broadcast communications, which result in more network traffic and a waste of system resources. In this paper, we study routing evaluation criteria for multicast communication under different switching technologies. Multicast communication in multicomputers is formulated as a graph theoretical problem. Depending on the evaluation criteria and switching technologies, we study three optimal multicast communication problems, which are equivalent to the finding of the following three subgraphs: optimal multicast path, optimal multicast cycle, and minimal Steiner tree, where the interconnection of a multicomputer defines a host graph. We will show that all these optimization problems are NP-complete for the popular 2D-mesh and hypercube host graphs. Heuristic multicast algorithms for these routing problems are proposed. © 1993 IEEE