Nader F. Mir

A survey of data multicast techniques, architectures, and algorithms

This article presents a survey of architectures, techniques, and algorithms for multicasting data in communication switching networks. We start with a broadcast architecture using a separate copy network and a routing network. A few versions of this idea using Delta and Benes networks exist. Another multicast architecture is a recycling network where internal nodes act as relay points, accept packets from the switching fabric, and recycle them back into the fabric after relabeling the packets. Next, we give an overview of a system that uses the Boolean splitting multicast algorithm. In this system a nonblocking self routing broadcast banyan copy network has been proposed. The network consists of several components including a running adder network to generate running sums of copy numbers specified in the headers of input packets. We then describe a multicasting technique presented for a different class of switching networks called deflection-routing networks. Finally, the idea of extending a nonblocking network to a three-dimensional structure consisting of multiple parallel planes is also presented. At the end of this article, we compare the efficiencies of the presented multicast architectures.

Simulation of voice over MPLS communication networks

This paper presents analytical models for voice over IP with applications on multiprotocol label switching (MPLS) networks. Models are developed to measure the efficiency of the voice packets transmission over IP. For handling delay-sensitive packets such as voice packets, the voice back-bone of the systems to be analyzed eliminates the use of buffers on voice traffic. The network node models presented in this paper support the quality of service (QoS) requirements and traffic engineering standards supported by MPLS. The performance results in terms of voice delay and blocking probability are presented.

Analysis of nonuniform traffic in a switching network

This paper evaluates the performance of a switching network using nonuniform traffic models. The switching network is presented using the Benes (1965) topology and buffered switch elements. The nonuniform traffic refers to a traffic model with unevenly distributed routing and different intensity at certain output port destinations. The performance of the buffered network is analyzed applying nonuniform traffic in the form of hot-spot and community-of-interest. An analytical queueing model is developed for performance evaluation. Results of the performance evaluation on the network throughput and delay are presented.

ANALYSIS OF A HIGH-SPEED INTERCONNECTION NETWORK

A thorough routing analysis of a switching network called the spherical switching network for high-speed applications is presented in this paper. The spherical switching network has a cyclic, regular, and highly expandable structure with a simple self-routing scheme. The network is constructed with fixed-size switch elements regardless of the size of the network. Each switch element consists of a carefully-selected sized 9 input/output crossbar and a local controller. One of the nine pairs of links is external and carries the external traffic, and the other eight pairs are internal. The contention resolution in each switch element is based on deflection of losing packets and incremental priority of packets. The switch elements do not utilize any buffering within the network. The analysis shows that this network clearly outperforms typical interconnection networks currently being deployed in practical switches and routers such as Banyan network. In order to keep the number of deflections low, each incoming external link is connected to a buffer with flow control capabilities. Due to the special arrangement of interconnections in the network, a much larger number of shortest paths between each pair of source/destination exists. The related analysis for finding the number of hops and shortest paths appear in this paper.

Efficient architectures and algorithms for multicasting data in computer communication networks

This paper presents two network architectures with associated routing and multicast algorithms for improved performance under multicasting traffic conditions. A conditionally nonblocking network, referred to as a Clos network, forms the basis for the development of efficient multicast communication networks. The Clos network is first analyzed under multicast traffic conditions for blocking and multicast overflow probability. The analysis determines the overflow probability under two different multicast distribution assumptions. The first distribution assumes all packets request the same number of copies and the second distribution uses a random number of requested copies. An analysis of an extension of the presented network to multiplexed parallel planes of a network shows a significant improvement on the network performance and particularly on the carried traffic load when compared with previously published multicast architectures using different buffering strategies.

Analysis of fault-tolerant multipath crossbars

This paper presents design and comprehensive analysis of high-performance crossbars where crossbars can be asymmetrical in size, buffered at all crosspoints, and capable of multipath routing and crosspoints are fault-tolerant. A crossbar, as a building block of switching networks, with the mentioned features in its structure can demonstrate fault-tolerant property. This property is a major factor for crossbars to perform efficiently in modern data networks. A generic condition of n /spl times/ k crossbar with n inputs (rows), k columns, and n outputs (rows) under which a crossbar becomes multipath is examined. In a multipath crossbar a packet can be routed through k different paths to an output. The multipath feature ensures the property of fault-tolerance and provides a faster congestion resolution especially under the multicast traffic. This paper also describes a two-dimensional Markov chain associated with the crossbars queueing model, and presents the performance evaluation of crossbars.

An efficient switching system for next-generation large-scale computer networking

A switching fabric called the spherical switching network (SSN) for high-speed applications in next-generation networking is introduced. The performance evaluation and comparison show that this network clearly outperforms typical interconnection networks currently being deployed in practical switches and routers such as a multi-stage network. The spherical switching network has a cyclic, regular, and highly expandable structure with a simple self-routing scheme. The network is constructed with fixed-size switch elements regardless of the size of the network. Each switch element consists of a carefully-selected sized 9 /spl times/ 9 crossbar and a local controller. One of the nine pairs of links is external and carries the external traffic, and the other eight pairs are internal. The contention resolution in each switch element is based on deflection of losing packets and incremental priority of packets. In order to keep the number of deflections low, each incoming external link is connected to a buffer with flow control capabilities. Due to the special arrangement of interconnections in the network, the network operates efficiently since the occurrence of deflections is dramatically reduced.

An efficient switching fabric for next-generation large-scale computer networking

In this paper, a switching fabric called the spherical switching network for high-speed applications in next-generation networking is introduced. The performance evaluation and comparison show that this network clearly outperforms typical interconnection networks currently being deployed in practical switches and routers. The spherical switching network has a cylic, regular, and highly expandable structure with a simple self-routing scheme. The network is constructed wit fixed-size switch elements regardless of the size of the network. Each switch element consists of a carefully selected sized 9 × 9 crossbar and a local controller. One of the nine pairs of links is external and carries the external traffic, and the other eight pairs are internal. The contention resolution in each switch element is based on deflection of losing packets and incremental priority of packets. In order to keep the number of deflections low, each incoming external link is connected to a buffer with flow control capabilities. Due to the special arrangement of interconnections in the network, the network operates efficiently since the occurrence of deflections is dramatically reduced.

Implementation of P2P File Sharing Using Bi-directional Chord Protocol Algorithm

One of the key components of achieving efficiency when looking up on resources is the success of peer-to-peer (P2P) applications. As the structured P2P is an efficient way to locate resources, our study performs two improvements in a structured P2P resource lookup protocol of Chord-based algorithms which is widely accepted. The proposed improvements in detail are presented using two methods. In the first method, the routing information for accurate search of resource is low. In this method, only clockwise direction of resource lookup can be implemented and a unique algorithm is designed for enhancing the finger table in a Chord. A counter-clockwise finger table is also included for generating resource queries in two direction clock wise and anticlockwise increasing the density of neighboring fingers. The proposed model also employs a new functionality of eliminating excess fingers generated by the inclusion of fingers by the suggested model. The results of simulation on effectiveness of the search in the proposed model against the average lookup hops and average lookup delay are presented. The model of algorithm context is extended as finger table resulting in forwarding-storm of routing maintenance messages.

Performance modeling of multimedia traffic in mobile wireless networks

This paper presents a handoff model for multimedia users in an wireless mobile network. Our emphasis in the performance evaluation is the factor of mobility with taking into account the speed status of a user. The performance results in terms of handoff blocking probability and channel blocking for different classes of calls are presented. Handoffs with mobility consideration including the alternation of states prior to reaching a cell boundary, the speed of mobile terminal, and the distance between a mobile terminal and a cell boundary are modeled. For instance, the level for requesting a handoff in a noise-limited area is -80 dBm in which situation a vehicle reaches the cell boundary or there is a signal obstruction within the cell site. Selected numerical results of the performance analysis and the probability of requiring a handoff are presented.