Performance Management in ATM Networks

ATM is representative of the connection-oriented resource provisioning classof protocols. The ATM network is expected to provide end-to-end QoS guaranteesto connections in the form of bounds on delays, errors and/or losses. Performancemanagement involves measurement of QoS parameters, and application of controlmeasures (if required) to improve the QoS provided to connections, or to improvethe resource utilization at switches. QoS provisioning is very important for realtimeconnections in which losses are irrecoverable and delays cause interruptionsin service. QoS of connections on a node is a direct function of the queueing andscheduling on the switch. Most scheduling architectures provide static allocationof resources (scheduling priority, maximum buffer) at connection setup time. Endto-end bounds are obtainable for some schedulers, however these are precluded forheterogeneously composed networks. The resource allocation does not adapt to theQoS provided on connections in real time. In addition, mechanisms to measurethe QoS of a connection in real-time are scarce.In this thesis, a novel framework for performance management is proposed. Itprovides QoS guarantees to real time connections. It comprises of in-service QoSmonitoring mechanisms, a hierarchical scheduling algorithm based on dynamicpriorities that are adaptive to measurements, and methods to tune the schedulers atindividual nodes based on the end-to-end measurements. Also, a novel scheduler isintroduced for scheduling maximum delay sensitive traffic. The worst case analysisfor the leaky bucket constrained traffic arrivals is presented for this scheduler. Thisscheduler is also implemented on a switch and its practical aspects are analyzed.In order to understand the implementability of complex scheduling mechanisms,a comprehensive survey of the state-of-the-art technology used in the industry isperformed. The thesis also introduces a method of measuring the one-way delayand jitter in a connection using in-service monitoring by special cells

Design of traffic shaper / scheduler for packet switches and DiffServ networks : algorithms and architectures

The convergence of communications, information, commerce and computing are creating a significant demand and opportunity for multimedia and multi-class communication services. In such environments, controlling the network behavior and guaranteeing the user\u27s quality of service is required. A flexible hierarchical sorting architecture which can function either as a traffic shaper or a scheduler according to the requirement of the traffic load is presented to meet the requirement. The core structure can be implemented as a hierarchical traffic shaper which can support a large number of connections with a wide variety of rates and burstiness without the loss of the granularity in cells\u27 conforming departure time. The hierarchical traffic shaper can implement the exact sorting scheme with a substantial reduced memory size by using two stages of timing queues, and with substantial reduction in complexity, without introducing any sorting inaccuracy. By setting a suitable threshold to the length of the departure queue and using a lookahead algorithm, the core structure can be converted to a hierarchical rateadaptive scheduler. Based on the traffic load, it can work as an exact sorting traffic shaper or a Generic Cell Rate Algorithm (GCRA) scheduler. Such a rate-adaptive scheduler can reduce the Cell Transfer Delay and the Maximum Memory Occupancy greatly while keeping the fairness in the bandwidth assignment which is the inherent characteristic of GCRA. By introducing a best-effort queue to accommodate besteffort traffic, the hierarchical sorting architecture can be changed to a near workconserving scheduler. It assigns remaining bandwidth to the best-effort traffic so that it improves the utilization, of the outlink while it guarantees the quality of service requirements of those services which require quality of service guarantees. The inherent flexibility of the hierarchical sorting architecture combined with intelligent algorithms determines its multiple functions. Its implementation not only can manage buffer and bandwidth resources effectively, but also does not require no more than off-the-shelf hardware technology. The correlation of the extra shaping delay and the rate of the connections is revealed, and an improved fair traffic shaping algorithm, Departure Event Driven plus Completing Service Time Resorting algorithm, is presented. The proposed algorithm introduces a resorting process into Departure Event Driven Traffic Shaping Algorithm to resolve the contention of multiple cells which are all eligible for transmission in the traffic shaper. By using the resorting process based on each connection\u27s rate, better fairness and flexibility in the bandwidth assignment for connections with wide range of rates can be given. A Dual Level Leaky Bucket Traffic Shaper(DLLBTS) architecture is proposed to be implemented at the edge nodes of Differentiated Services Networks in order to facilitate the quality of service management process. The proposed architecture can guarantee not only the class-based Service Level Agreement, but also the fair resource sharing among flows belonging to the same class. A simplified DLLBTS architecture is also given, which can achieve the goals of DLLBTS while maintain a very low implementation complexity so that it can be implemented with the current VLSI technology. In summary, the shaping and scheduling algorithms in the high speed packet switches and DiffServ networks are studied, and the intelligent implementation schemes are proposed for them

Connection utilization masking in ATM networks

A technique for connection utilization masking in ATM networks is presented, modeled, and analyzed. Specifically, a cell injection mechanism is modeled with a two-state Markov Modulated Poisson Process (MMPP) to study its autocorrelation and power spectral density properties and the queue response to the arrival process. The Cruz bound is used to determine injection source traffic parameters. Cell injection is implemented on a permanent virtual channel with a bursty Variable Bit Rate (VBR) source. The result is also VBR traffic having a new set of user-defined statistics. Traffic traces representing before and after injection scenarios are collected and further processed to define autocorrelation and power spectrum density functions. The results are used to compare and justify analytical results. The cell-injected stream shows strong correlation over a long duration, an indication of the removal of burstiness. Cell Transfer Delay, Cell Loss Rate, and Cell inter-arrival time statistics are collected to evaluate injection's effects on Quality of Service (QoS) parameters. Cell injection causes more mid- and high-frequency traffic power to be shifted towards low frequency region in the frequency spectrum, representing an increase in the mean arrival rate.http://www.archive.org/details/connectionutiliz00cayaFirst Lieutenant, Turkish ArmyApproved for public release; distribution is unlimited

Management of Carrier Grade Intra-Domain Ethernet

Internet ei ole enää pelkkä tiedonlähde, vaan enenevässä määrin kriittisempi osa yhteiskunnan infrastruktuuria. Nykyiset Internet-palveluja tuottavat teknologiat - IPv4 osoitteistuksessa, MPLS siirtoalustana ja SDH fyysisenä välitysteknologiana - ovat alkaneet menettää valta-asemaansa samalla kun kaikille tuttu verkkoteknologia, Ethernet, on laajentunut lähiverkoista runkoverkkoihin. Maailmassa on miljoonia Ethernet-lähiverkkoja. Olisi kustannustehokaampaa toteuttaa myös näiden lähiverkkojen väliset siirtoyhteydet Ethernetillä. Halu kustannustehokkuuteen ja teknologian konsolidointiin on tuonut esille tarpeen ns. operaattorikestoisille Ethernet-palveluille. Koska Ethernetistä puuttuu määrättyjä ominaisuuksia joita ilman on mahdotonta toteuttaa siirtoverkkopalveluja, näitä operaattori-Ethernet-palveluja on tuotettu toistaiseksi olemassa olevilla tekniikoilla, kuten MPLS:llä. Tulevaisuudessa todellinen haaste on luoda operaattoritasoinen, Ethernet-pohjainen siirtoverkkoteknologia, joka kykenee tuottamaan Ethernet-palvelujen lisäksi mitä tahansa muita tietoliikennepalveluja. Tämä diplomityö käsittelee operaattoritasoisen Ethernetin hallintaa yhden runkoverkkoalueen sisällä. Työssä käydään läpi standardoidut operaattorikestoiset Ethernet-palvelut, teknologiat joilla palveluja tällä hetkellä tuotetaan, ehdokkaat tulevaisuuden Ethernet-siirtoverkkoteknologioiksi sekä keskeisimmät verkonhallintaan liittyvät standardit. Työn jälkimmäisessä puoliskossa esitellään Euroopan Unionin 7th Framework ETNA -projektia varten kehitetty verkonhallintajärjestelmä. Hallintajärjestelmä tarjoaa rajapinnan jonka kautta on mahdollista provisioida suojattuja Ethernet-palveluja kahden asiakasliityntäpisteen välillä, ja lisäksi lähetyspuita joissa kohteina on useampi asiakaspiste. Hallintajärjestelmältä tilatut palvelut viestitetään Ben Gurionin yliopiston toteuttaman, verkkoprosessoreilla toimivan välityskerroksen välitystauluihin.Internet is evolving from its role as a mere information provider to an ubiquitous infrastructure crucial to society. The current technologies running the majority of global Internet - IPv4 in addressing, MPLS as core transport and SDH as the physical transfer technology - have been long-lived. However, their dominance has started to diminish because a network technology common to all, Ethernet, has started to expand from local to metropolitan and wide area networks. Most enterprises and home users already use Ethernet in their LAN. Connecting these sites to MAN or WAN with the same technology is the logical next step in technology consolidation. This has raised the demand for Carrier Ethernet services. However, internally they are still mostly provided with non-Ethernet technologies such as MPLS or SDH, because currently Ethernet lacks the necessary service assurance components. The real challenge in future internetworking is creating a Carrier Ethernet Transport (CET). With CET, any imaginable telecommunication service is delivered with a purely Ethernet based technology. When we have Ethernet in transport networks, it is no more a long stretch to a global, routed end-to-end Ethernet. This thesis covers management of an intra-domain CET control plane. First, Carrier Ethernet services and technologies currently producing these services are analyzed. Second, requirements imposed to CET and current CET candidates are discussed. Third, network management standards and their alignment to carrier business is studied. After the background has been discussed, a control plane management system developed for the EU 7th framework ETNA project is introduced. The management system is capable of provisioning point-to-point and multipoint services and is controlled via a web-service -based northbound interface. The control plane is able to install the services as forwarding entries in a network processor -driven data plane developed at Ben Gurion University

Traffic control mechanisms with cell rate simulation for ATM networks.

PhDAbstract not availabl

Resource allocation in ATM networks

The areas of resource allocation ancl congestion control in ATM networks have been investigated. ATM networks and the guarantees given to users have been reviewed and a new model of ATM networking has been proposed. To aid the analysis of ATM network issues, performance modelling and simulation methods have been reviewed. Typical sources have been designed : a two-state Markov model for voice ; a multi-state Markov one layer variable bit rate video source model ; an empirical file transfer data source model ; and some basic network elements. The models have been verified and validated on a discrete event simulator. It was shown that there are problems when using ATM over satellite links. A model for the noise analysed from real satellite links was developed. Based on this model a new more efficient protocol for assembling ATM cells was proposed and simulated. Again at the cell level, the traffic that can pass the standardised conformance test and still produce the worst performance in the network was investigated. Counter to the traditional wisdom it was found that the on-off source does not always produce the worst case traffic. Users have been classified with new parameters, and it has been shown that these new classes of users can still be given guarantees without giving traffic descriptors. Adaptive user classes have been modelled mathematically. A new model for efficiency has been developed, which includes both network issues and economic issues. This new model defines congestion and also describes how to allocate resources when congested. It has been shown that this economic model coupled with the adaptive user classes allow for an increase in both network and economic efficiency simultaneously for some sample cases

ATM network impairment to video quality

Includes bibliographical reference

Mobile network design : Orange UK 2G to 3G mobile backhaul evolution

The research presented in this thesis is focused on the evolution of a GSM/GPRS (2G) cellular mobile network to UMTS (3G) and then subsequently, HSDPA. The particular technical area of research relates to the mobile backhaul network which provides the connectivity between radio cell sites which support the wide area radio coverage, and the mobile network operator’s core network. Due to the evolution of UMTS with HSDPA, the research covers the initial UMTS network rollout and then addresses the evolution of this infrastructure to support mobile broadband communications, through the introduction of HSDPA as a network upgrade. The two research questions being addressed are therefore: •How is it possible to evolve a GSM/GPRS mobile backhaul network to support a converged GSM/GPRS and UMTS cellular mobile service? •How is it possible to ensure scalability of the converged backhaul network given the introduction of HSDPA and associated mobile broadband data growth? The starting point of the research is an established GSM and GPRS commercial network in the UK and the study is based on the design of the Orange network and focused on the period 2000 to 2010. During this period the author was working as Principal Network Designer within Orange and had overall responsibility for the strategy, architecture and design of the UK mobile backhaul network. The thesis provides a detailed explanation of the novel network design that was adopted and how it was evolved throughout the ten year period covered by the research. The research proves that the original static TDM approach was not suitable for UMTS and therefore the outcome was the introduction of an ATM network with optimisation based on traffic class rt-VBR over protected STM-1 transmission links. HSDPA drove further traffic growth and resulted in an evolution of the solution to ensure massive scalability was supported through the migration to Carrier Ethernet and implementation of pseudo-wires. In addition, to providing a technical description of the network design, the thesis also aims to provide a historical record of the technologies and equipment used during this period of rapid change within the UKs mobile networks