I
The Future will not remember.
The Future will not remember.
The Future will not remember.
The Future will not remember.
The past does not forget.
The past does not forget.
The past does not forget.
The past does not forget.
II
R R R
RINGRAZIAMENTI INGRAZIAMENTI INGRAZIAMENTI INGRAZIAMENTI
Ogni opera, dalla più semplice alla più elaborata, è fortemente intrisa di chi la crea - e una tesi di laurea ha in sé lo stato d’animo di un percorso denso di anni e di eventi. Anni ed eventi belli, per i quali ringrazio Pisa, componendo questo mio lavoro sulla rete in fibra ottica che collega Ingegneria al CNR, passando al di sotto delle strade della città, che mille volte ho percorso.
Chi mi ha proposto l’argomento di questo studio è il Prof. Michele Pagano, al quale vanno i miei più sentiti ringraziamenti.
Un secondo importante grazie va all’Ing. Davide Adami per la costante disponibilità durante l’esperienza di tirocinio e per avermi permesso di svolgere le attività di testing degli apparati Marconi in collaborazione con il CNIT di Pisa.
Sempre in ambito di tirocinio, desidero citare Andrea Luchini per la collaborazione, per il tempo dedicatomi e per avermi suggerito idee, consigli e correzioni che hanno contribuito alla creazione di questa tesi. Insieme ad Andrea ringrazio, inoltre, i ragazzi del laboratorio di Reti di TLC, per il simpatico periodo trascorso insieme.
Non posso non ringraziare il Prof. Stefano Giordano per aver fatto nascere in me l’interesse e la curiosità che mi hanno spinto ad approfondire le mie conoscenze sugli argomenti legati alle reti di telecomunicazioni.
Ringrazio inoltre i ragazzi del CNIT - l’Ing. Filippo Cugini e l’Ing. Francesco Paolucci in particolare - per avermi aiutato nel risolvere piccoli problemi e dubbi legati alla strumentazione e soprattutto per avermi dato modo di apprezzare l’importanza della collaborazione di gruppo.
Infine, un grazie di cuore a tutti coloro, e sono molti, che coi loro volti e le loro parole hanno animato tutto il mio percorso di studi universitari, dandomi spunti positivi e negativi – perché ciò che sono oggi lo devo a loro.
III
ABSTRACT ABSTRACT ABSTRACT ABSTRACT
Optical networks are the basic architecture by which the Internet can reach every single place on earth. DWDM (Dense Wavelength Division Multiplexing) networks are the actual and future instrument to let a large number of users access the Web by different wavelengths over a single pair of fiber cables, using optical technologies. The actual backbone networks are being reconfigured in order to have a DWDM deep core and to keep old Sonet/SDH architectures in the peripheral parts of the infrastructure.
The cost of new fiber cables is always too high for any company when compared to the more convenient and scalable solution of an optical multiplexer. This thesis includes some tests on the Marconi-Ericsson’s PMA32 Optical Add-drop Multiplexer, which have been faced in order to implement a 3 nodes’ optical core connecting the Information Engineering Dept. to the national CNR throughout the city of Pisa (Italy).
The main subjects of this preliminary analysis have been: the software procedures required by the PMA32 OADMs to create cross-connections and pass-through- connections, the power levels of the optical components, parameters such as the
%bandwidth, the packet loss and the maximum transfer delay - which have been measured by an AX4000 traffic generator & tester, and finally the protection features of the PMA32 in case of failure or fault.
Both point-to-point links and ring structures have been tested in this book. The implementation of a 3 PMA32s network allowed to analyze the effective delays due to the fiber cable ring and to a single PMA32.
As final applications on the implemented architecture, we included the transmission of multiple video traffic through the optical ring and some Topology Discovery/Performance Information Services for optical Grid computing.
This book has the purpose to be an easy-to-use and immediate guide to operators or companies about the PMA32 or more recent families by Marconi-Ericsson, but also a case study about metro/regional core networks and an interesting guide to the actual evolution of optical fiber and backbone networks in the age of the Internet.
IV
SOMMARIO SOMMARIO SOMMARIO SOMMARIO
Le reti ottiche di trasporto sono l’architettura di base per mezzo della quale Internet può raggiungere ogni luogo del pianeta; in particolare le reti DWDM (Dense Wavelength Division Multiplexing) sono lo strumento attuale e del prossimo futuro per permettere ad un gran numero di utenti di accedere al mondo Web mediante diverse lunghezze d’onda su un unico paio di fibre ottiche. Le attuali dorsali vengono riconfigurate in modo da avere un core in tecnologia DWDM, con le vecchie architetture Sonet/SDH nelle zone periferiche delle dorsali stesse.
Il costo di nuove fibre è sicuramente molto più alto se comparato con la più conveniente e scalabile soluzione di un multiplexer ottico. Questa tesi include vari test sull’Add-drop multiplexer ottico PMA32 di Marconi-Ericsson, che sono stati fatti con lo scopo di implementare una rete ottica a 3 nodi per collegare il Dipartimento di Ing. dell’Informazione con il CNR attraverso il centro-città di Pisa.
I più importanti argomenti oggetto di questa analisi preliminare sono stati: le procedure software necessarie per creare cross-connections e pass-through- connections tramite il PMA32, i livelli di potenza dei componenti ottici, parametri come la bandwidth, la perdita di pacchetti e il ritardo massimo di trasferimento - che sono stati misurati con un generatore/tester di traffico, e infine i meccanismi di protezione del PMA32 in caso di guasto o danneggiamento.
Sono stati testati sia link punto-punto sia strutture ad anello. L’implementazione di una rete a 3 PMA32 ha permesso di analizzare i ritardi effettivi dovuti ai cavi in fibra ottica e ad un singolo PMA.
Come applicazioni finali sull’architettura implementata sono stati inclusi in questo libro la trasmissione di flussi video multipli attraverso l’anello ottico, e alcuni servizi di Topology Discovery/Performance Information per Grid Computing ottico.
Questo testo intende essere una guida semplice ed immediata per operatori o compagnie sul PMA32 e sulle più recenti famiglie Marconi-Ericsson, ma anche un caso interessante di metro/regional core, ed una interessante guida sull’attuale evoluzione della fibra ottica e delle dorsali nell’era di Internet.
V
CONTENTS CONTENTS CONTENTS CONTENTS
Abstract III
Sommario IV
Introduction X
Chapter 1 - OPTICAL FIBER & DWDM TECHNOLOGY 1 1.1 PROPAGATION OF SIGNALS IN OPTICAL FIBER 1 1.1.1 SINGLE & MULTI-MODE FIBERS 2
1.1.2 LOSS & BANDWIDTH 2
1.1.3 CHROMATIC DISPERSION 4
1.2 OPTICAL COMPONENTS 5
1.2.1 COUPLERS 5
1.2.2 ISOLATORS & CIRCULATORS 7
1.2.3 WAVELENGTH MULTIPLEXERS & FILTERS 7 1.2.4 DIFFRACTION & REFLECTION GRATINGS 9 1.2.5 HIGH CHANNEL COUNT MULTIPLEXER ARCHITECTURES 10
1.2.6 OPTICAL AMPLIFIERS 13
1.2.7 OPTICAL TRANSMITTERS 15
1.2.8 OPTICAL DETECTORS 16
1.2.9 OPTICAL SWITCHES 17
1.2.10 WAVELENGTH CONVERTERS (TRANSPONDERS) 20
1.3 WDM ALL-OPTICAL NETWORKS 21
1.3.1 COMPARING OPTICAL POINT-TO-POINT LINKS AND
COMPLEX OPTICAL NETWORKS 21
1.3.2 WAVELENGTH PLANNING IN WDM & IN THE PMA32 21 1.3.3 TRANSPARENCY ADVANTAGES IN WDM SYSTEM 22 1.3.4 CLIENT LAYERS OF THE OPTICAL NETWORK 22
VI
1.4 WDM MAIN COMPONENTS 25
1.4.1 OPTICAL LINE TERMINALS (OLT’s) 27
1.4.2 OPTICAL LINE AMPLIFIERS 28
1.4.3 OPTICAL ADD-DROP MULTIPLEXERS (OADM’s) 28
1.4.4 OPTICAL CROSSCONNECTS (OXC’s) 32
1.5 PERFORMANCE & FAULT MANAGEMENT 33
1.5.1 CONTROL AND MANAGEMENT 34
1.6 DEPLOYMENT OF OPTICAL NETWORKS 35
1.6.1 THE SONET/SDH CORE NETWORK 35
1.6.2 ARCHITECTURAL CHOICES FOR NEXT-GENERATION
TRANSPORT 37
1.7 DWDM TECHNOLOGY 38
Chapter 2 - THE PMA32 OPTICAL ADD-DROP MULTIPLEXER 43
2.1 INTRODUCTION TO THE PMA-32 43
2.2 MECHANICAL DESCRIPTION 45
2.3 MULTIPLEXING/DEMULTIPLEXING IN THE PMA-32 46 2.3.1 QUICK INTRODUCTION TO THE SYSTEM UNITS 46
2.3.2 INTERNAL TRAFFIC ARCHITECTURE 47
2.3.3 CHANNEL FREQUENCIES 51
2.4 THE CONCEPT OF CROSS-CONNECTIONS 52
2.5 PMA-32 ALARMS 53
2.5.1 THE MOST COMMON ALARMS 54
2.6 TRAFFIC PROTECTION 58
2.7 OPERATOR CONTROL 58
Chapter 3 - TESTING THE PMA32 60
3.1 PMA-32 CONFIGURATION 60
3.1.1 HOW TO CREATE A CROSS-CONNECTION 60 3.1.2 HOW TO DELETE A CROSS-CONNECTION 67
VII 3.1.3 HOW TO CREATE A SIMPLE PASS-THROUGH 67
3.1.4 HOW TO DELETE A PASS-THROUGH 69
3.1.5 HOW TO CONFIGURE/UNCONFIGURE A TRANSPONDER 69
3.2 “ANALOGUE MONITOR DISPLAY” 76
3.2.1 ANALOGUE MONITORING ON A SINGLE PMA
Using only 1 frequency 76
3.2.2 ANALOGUE MONITORING ON A POINT-TO-POINT LINK
including two PMA’s – Using only 1 frequency 83 3.2.3 CONCLUSIONS ABOUT THE ANALOGUE MONITORING 89
3.3 AX4000 as PMA-32 TESTER 91
3.3.1 BRIEF INTRODUCTION TO THE AX4000 91 3.3.2 SENDING TRAFFIC ON A POINT-TO-POINT LINK
BETWEEN 2 PMA-32 ’s 94
3.4 SNC PROTECTION IN THE PMA-32 106
3.4.1 SNC PROTECTION MECHANISM 106
3.4.2 EXPERIMENTS ON A RING INVOLVING 2 PMA’s 110 3.5 MULTIPLEXING ON A POINT-TO-POINT LINK (2PMA’s) 121
3.5.1 INTRODUCTION 121
3.5.2 GENERAL SITUATION 123
3.5.3 TRAFFIC PERFORMANCE 128
3.5.4 LATENCY VALUES 137
3.5.5 ANALOGUE MONITORING POWER VALUES
with a MULTIPLEXED SIGNAL 141
3.6 WHEN A CARD DOESN’T WORK PROPERLY 142
Chapter 4 - IMPLEMENTATION OF A CORE INVOLVING 3 PMA32’s 146 4.1 MULTIPLEXING ON A RING INVOLVING 3 PMA’s 146 4.2 THE PHYSICAL LAYER GOAL: A 3 PMA’s OPTICAL CORE 148 4.2.1 CONFIGURATION OF THE 3 INVOLVED PMA’s 148 4.2.2 LATENCY VALUES IN THE POSSIBLE TOPOLOGIES 155 4.3 COMPUTER NETWORKS BASED ON OPTICAL CORES with PMA’s 163
VIII 4.3.1 AN ADD-DROP OPERATION REQUIRING 2 FREQUENCIES 163 4.3.2 CONFIGURATION OF THE NETWORK/TRANSPORT LEVELS 164 4.3.3 DOUBLE FILE TRANSFER ON OPPOSITE DIRECTIONS 166 4.3.4 MULTIPLEXED TRAFFIC FOR A DOUBLE FILE TRANSFER 167 4.4 PMA-32 AS OPTICAL CORE FOR A GRID COMPUTING TESTBED 169
4.4.1 GLOBAL GRID COMPUTING 169
4.4.2 TOPOLOGY DISCOVERY SERVICE 169
4.4.3 FD-TDS PERFORMANCE EVALUATION 172
4.4.4 CONCLUSION 174
Chapter 5 - FROM THE PMA32 TO THE NEW OMS FAMILIES 175
5.1 PMA-32 UTILIZATION 175
5.1.1 THE LAUNCH (1999) 175
5.1.2 THE PMA-32 IN GENOA’s G8 SUMMIT (2001) 175
5.2 FROM THE PMA32 TO THE NEW OMS FAMILIES 177
5.2.1 MARCONI-ERICSSON PRESENT THE HEIR OF THE PMA-32:
THE MHL3000 (2006) 177
5.2.2 THE MARCONI-ERICSSON PRODUCT PORTFOLIO TODAY 180
5.2.3 THE OMS 1400 (2007) 182
Chapter 6 - THE EVOLUTION OF BACKBONE NETWORKS 184 6.1 BACKBONE NETWORKS BASED ON “SDH over OPTICAL” 184
6.1.1 THE WIND-INFOSTRADA SOLUTION 184
6.1.2 THE ALBACOM SOLUTION 187
6.2 MARCONI-ERICSSON’s OMS/MHL3000 IN THE
TELECOM ITALIA’s BACKBONE 188
6.2.1 TELECOM ITALIA’s EVOLUTION STRATEGY (Since 2003) 188 6.2.2 TELECOM ITALIA’s PHOENIX ARCHITECTURE 190 6.3 THE GigaPop PROJECT WITH PMA32s by Marconi IN PISA 193 6.4 MARCONI-ERICSSON’s PMA32 IN EUROPEAN BACKBONES 194
IX
6.5 OPTICAL WORLDWIDE BACKBONES 195
Conclusions 198
References 199
List of Figures 201
X
INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION
One of the big technological challenges for the very next future is to reach large capacities in data traffic throughout mesh backbone networks. We can think of backbone networks as private architectures owned by a single or more than one provider which constitute the main road by which optical signals carry long distance voice/data traffic. To identify the concept, they can be viewed as railway networks owned by different companies which spread throughout a territory. To connect the different local areas to the main structure of these backbones OADMs (Add Drop Multiplexers) and OXCSs (Optical Cross Connects) are deployed: the former is a standard which allows to insert or drop a single traffic flow, the latter is a component used to interconnect many rings to the main infrastructure.
PMA32 by Marconi-Ericsson is an OADM and had an important role in the development of the Marconi photonic brand – which is today part of the Ericsson group – and in the creation of a large portfolio of different products for the deploying and the maintenance of optical point-to-point links, rings or mesh networks.
To deeply penetrate the interesting subject and to valuate the hardware involved in this project it was necessary to shortly analyze the optical components used to build optical networks. Chapter 1 is about the general features of optical DWDM networks that can be useful to understand the PMA32’s architecture. We’re going to see which components are used to transmit and to receive the optical channels, which kind of multiplexers or demultiplexers can be created with the actual optical techniques, and the EDFA amplifiers’
features. Other interesting elements are the DWDM basics and the control & management of optical networks.
Chapter 2 is a brief presentation about the PMA32 OADM, explaining its mechanical structure, the internal traffic architecture, the MUX/DEMUX mechanism, the cross- connection and pass-through connection concepts and also the most common alarms raised up by the PMA32 itself. This book is also supposed to be an easy-to-use guide to operators on optical networks.
The testing of the PMA32 is analyzed in Chapter 3: after a configuration of the cross- connections / pass-through connections and of the transponding / TX / RX cards, we are explaining the software provided by Marconi, which allows to monitor the power levels at each component of the machine. We’re going to valuate the impact of an AX4000 traffic generator/analyzer and of a router tester on the PMA32, when sending different kinds of traffic flow. The main network performance parameters will be encountered by these tests.
This chapter will also introduce the main concepts about protection on a link/ring, provided by the PMA32 to let the network work correctly even after a fault or failure.
Finally we’ll implement an optical ring involving 2 PMAs, measuring the loss of packets when a failure happens, and the packet latency in different configurations of the optical paths.
Chapter 4 describes the implementation of our final goal: an optical network involving 3 PMA32s and a multiplexed signal consisting of two Gigabit Ethernet flows and an ATM/SONET flow. We will valuate the obtained optical core calculating the latency values throughout the ring, thus tracing the optical architecture’s complexity; besides we will test a video streaming from a computer at one end of the ring to a second one at the other end.
Grid computing applications will complete this chapter as an interesting scenario for the optical infrastructure just implemented.
XI We are going to see in a short presentation the families of products produced by Ericsson after the PMA32; Chapter 5 is to be a simple view on the Ericsson’s actual portfolio.
Chapter 6 concludes this book with a wide selection of backbone networks implemented in Italy and Europe by some providers. The main subject of the chapter is to locate the PMA and the following families in the general situation of mesh all-optical networks deployed in local, metro, regional and national areas, trying to trace the future challenges and trends about backbone networks and their more and more simplified protocol layering.
With this book I’m going to explain months of work to the reader, step by step, as simply as possible, not only showing the results of the activity, but also highlighting the most important features of this fascinating subject.
