QoS multicast tree construction in IP/DWDM optical internet by bio-inspired algorithms

Copyright @ Elsevier Ltd. All rights reserved.In this paper, two bio-inspired Quality of Service (QoS) multicast algorithms are proposed in IP over dense wavelength division multiplexing (DWDM) optical Internet. Given a QoS multicast request and the delay interval required by the application, both algorithms are able to find a flexible QoS-based cost suboptimal routing tree. They first construct the multicast trees based on ant colony optimization and artificial immune algorithm, respectively. Then a dedicated wavelength assignment algorithm is proposed to assign wavelengths to the trees aiming to minimize the delay of the wavelength conversion. In both algorithms, multicast routing and wavelength assignment are integrated into a single process. Therefore, they can find the multicast trees on which the least wavelength conversion delay is achieved. Load balance is also considered in both algorithms. Simulation results show that these two bio-inspired algorithms can construct high performance QoS routing trees for multicast applications in IP/DWDM optical Internet.This work was supported in part ny the Program for New Century Excellent Talents in University, the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1, the National Natural Science Foundation of China under Grant no. 60673159 and 70671020, the National High-Tech Reasearch and Development Plan of China under Grant no. 2007AA041201, and the Specialized Research Fund for the Doctoral Program of Higher Education under Grant no. 20070145017

Architecture, design, and modeling of the OPSnet asynchronous optical packet switching node

An all-optical packet-switched network supporting multiple services represents a long-term goal for network operators and service providers alike. The EPSRC-funded OPSnet project partnership addresses this issue from device through to network architecture perspectives with the key objective of the design, development, and demonstration of a fully operational asynchronous optical packet switch (OPS) suitable for 100 Gb/s dense-wavelength-division multiplexing (DWDM) operation. The OPS is built around a novel buffer and control architecture that has been shown to be highly flexible and to offer the promise of fair and consistent packet delivery at high load conditions with full support for quality of service (QoS) based on differentiated services over generalized multiprotocol label switching

Optical Networks and the Future of Broadband Services

The evolution of broadband services will depend on the widespread deployment of optical networks. The deployment of such networks will, in turn, help drive increased demand for additional capacity. In this world, service providers will have a growing need to be able to flexibly adjust capacity to accommodate uncertain and growing demand. In this article, we present a cost model that highlights the advantages of new optical networking technologies such as Dense Wavelength Division Multiplexing (DWDM) over traditional architectures for optical networks. This analysis highlights the increased flexibility and scalability of DWDM networks, which lowers the deployment costs of such networks in light of growing and uncertain demand. The DWDM architecture holds the promise of allowing the emergence of wavelength markets, where traffic could be switched between service provider networks at the optical layer (without the need for multiple costly and wasteful electronic/optical conversions). While the DWDM and Optical Cross-Connect (OxC) technologies provide a technical infrastructure for supporting wavelength markets, additional developments are also likely to be required. This paper also considers some of the impediments to the growth of wavelength markets, namely the need for secondary markets and standardized contracts

Benchmarking and viability assessment of optical packet switching for metro networks

Optical packet switching (OPS) has been proposed as a strong candidate for future metro networks. This paper assesses the viability of an OPS-based ring architecture as proposed within the research project DAVID (Data And Voice Integration on DWDM), funded by the European Commission through the Information Society Technologies (IST) framework. Its feasibility is discussed from a physical-layer point of view, and its limitations in size are explored. Through dimensioning studies, we show that the proposed OPS architecture is competitive with respect to alternative metropolitan area network (MAN) approaches, including synchronous digital hierarchy, resilient packet rings (RPR), and star-based Ethernet. Finally, the proposed OPS architectures are discussed from a logical performance point of view, and a high-quality scheduling algorithm to control the packet-switching operations in the rings is explained

An assembly and offset assignment scheme for self-similar traffic in optical burst switching

Includes bibliographical references.Optical Burst Switching (OBS) is a viable technology for the next generation core network. We propose an FEC-assembly scheme that efficiently assembles self-similar traffic and a Pareto-offset assignment rather than a constant offset assignment. Two buffers, a packet buffer and a burst buffer, are implemented at the Label Edge Router (LER), buffering traffic in the electronic domain. The assembler, between the packet and burst buffers, is served by the packet queue while the assembler serves the burst queue. We outline advantages of why burst assembly cannot be implemented independent of offset assignment. The two schemes must be implemented in a complementary way if QoS is to be realized in an OBS network. We show that there is a direct relation between OBS network performance with burst assembly and offset assignment. We present simulation results of the assembly and offset assignment proposals using the ns2 network simulator. Our results show that the combination of the proposed FEC-Based assembly scheme with the proposed Pareto-offset assignment scheme give better network performance in terms of burst drop, resource contention and delay. Key to any traffic shaping is the nature traffic being shaped. This work also compares performance of both traditional exponential traffic with realistic Self-Similar traffic of Internet traffic on the proposed assembly and offset assignment schemes. In our simulations, we assume that all Label Switch Routers (LSR) have wavelength converters and are without optical buffers. We use Latest Available Unused Channel with Void Filling (LAUC-VF) scheduling scheme and use Just Enough Time (JET) reservation scheme

Future of asynchronous transfer mode networking

The growth of Asynchronous Transfer Mode (ATM) was considered to be the ideal carrier of the high bandwidth applications like video on demand and multimedia e-learning. ATM emerged commercially in the beginning of the 1990\u27s. It was designed to provide a different quality of service at a speed up 100 Gbps for both real time and non real time application. The turn of the 90\u27s saw a variety of technologies being developed. This project analyzes these technologies, compares them to the Asynchronous Transfer Mode and assesses the future of ATM

Performance analysis of a proposed hybrid optical network

This dissertation discusses a novel Hybrid Optical Network (HON) that can provide service differentiation based on traffic characteristics (i.e., packet, burst, and long-lived flow) with QoS guarantee not only in network layer, but also in physical layer. The DHON consists of sophisticated edge-nodes, which can classify, monitor, and dynamically adjust optical channels in the core layer as traffic variation. The edge nodes aggregate traffic, identifying end-to-end delay by ingress queuing delay or burst timeout. The network can estimate number of channels by arriving traffic intensity and distribution with estimated upper-bound delay. The core layer employs two parallel optical switches (OCS, OBS) in the same platform. Thanks to the overflow system, the proposed network enhances utilization with fewer long distance premium channels. The premium channel can quickly handle burst traffic without new channel assignment. With less overprovisioning capacity design, the premium channel enhances utilization and decrease number of costly premium channels. This research also proposes mathematic models to represent particular DHON channels (i.e., circuit, packet, and burst). We employ method of moments based on overflow theory to forecast irregular traffic pattern from circuit-based channel (i.e., M/M/c/c) to overflow channel, in which G/G/1 model based on Ph/Ph/1 matrix can represent the overflow channel. Moreover, secondary channel supports packet-based traffic over wavelength channel with two service classes: Class I based on delay sensitive traffic (i.e., long flow) and Class II for non-delay sensitive traffic (e.g., best effort). In addition, mixture of traffic in the wavelength channels is investigated based on M/G/1 and M/G/2 with specific service time distribution for particular class. Finally, we show our DHON based on (O-O-O) switching paradigm has improved the performance over typical (O-E-O) switching network architecture based on NSF topology

Performance Of Optical Label Switching Network With Multi Protocol Label Switching Implementation

Today, the phenomenal traffic growth of Internet leads to the dramatic expansion of the transmission lines in the Internet Protocol (IP) network. Fibre optics as the key of the future transmission networks has evolved to provide almost limitless information carrying capacity via its Wavelength Division Multiplexing (WDM) technology. However, the relatively sluggish development in switching technology which still operates in electronics domain might creates bottleneck in various part of the network. Thus, the concept of All-Optical Network has been introduced. Here a lot of approaches have been proposed to bring IP closer to the optics technology such as IP over WDM. On the other hand, IP technology itself has evolved from pure connectionless system to connection-oriented in order to cope with the Quality of Service (QoS) demanded by the end users. Thus, the concept of Multi Protocol Label Switching (MPLS) has been standardized to achieve this. In this thesis, connection-oriented Optical Label Switching (OLS) network implementing MPLS system has been proposed as a viable and future proof network architecture

OBGP based QoS analysis for optical virtual private network connection setup

In a computer network, clients work with different applications; hence there are requirement of speed, bandwidth, delay etc. The parameters are called as Quality of Service (QoS) parameters. QoS guarantees the performance in a network. To meet the growing demand of Optical Virtual Private Network (OVPN), the Internet Service Providers (ISP) should use multiple techniques which ensure the Quality of Service. For performing data communication between nodes in a network the path to be followed should be known. In this project, BGP/OBGP protocols have been discussed and using this protocol, paths have been found between routers. Then the optimal path is found out based on the path attributes. Also the paths are examined for QoS parameters and the best path is chosen. An OVPN model has been discussed and modified for performing Routing & Wavelength Assignment (RWA) function based on QoS requirement which is expressed in terms of Q-factor and trying to achieve minimum blocking probability of path. The objective of this project is to assign best connection between nodes as per the request from clients operating with various applications