book-foreword

Foreword

The day I first drafted a Foreword to this book one of my graduate students e-mailed me: “Here’s another one . . .

December 28, 2006

Asian Quake Disrupts Data Traffic

SEOUL, South Korea, Dec. 27 – Telecommunications across Asia were disrupted on Wednesday after an earthquake off Taiwan damaged undersea cables, jamming Internet services as voice and data traffic vied for space on smaller cables and slower satellite links. The quake disrupted services in Taiwan, Singapore, Hong Kong, South Korea and Japan, but a ripple effect was felt in other parts of the world. Many phone subscribers could not get through to Europe, regional telecommunications operators reported, as they raced to reroute their traffic to alternative lanes. ‘We are seeing really massive outages in a spread of countries in East and Southeast Asia,’ said Todd Underwood, chief operations and security officer at the Internet monitoring firm Renesys. . . .. (etc.)’

The report goes on to describe how financial companies and businesses in the region were hit hard and how online banking and communications between financial markets and traders were affected. Why my student said “another one” is much to the point: failures such as this, and even more bizarre and unpredictable ways in which communication networks are disrupted, are an almost daily occurrence. FCC statistics show that metro networks annually experience approximately 13 cuts for every 1000 miles of fiber, and long-haul networks experience 3 cuts for 1000 miles fiber. This may sound like a low risk on a per-mile basis, but even the lower rate for long-haul networks implies a cable cut every four days on average in a typical network with 30 000 route-miles of fiber. In the first four months of 2002 alone, the FCC logged 50 separate network outages throughout the United States with some very peculiar causes. Of course the most common cause of failure, construction-related dig-ups of fiber-optic cables, is so frequent (despite extensive measures at physical-layer protection) that a wry joke in the industry is to refer to the backhoe as a “Universal Cable Locator”. In other recent failures, a fire in a power transformer melted a fiber cable affecting 5000 customers for over 9 hours, a faulty optical amplifier brought down an OC-192 between Vancouver and Victoria, BC, for over 10 hours, a boat anchor cut a cable taking 9 days to return an OC-192 between Montreal and Halifax back to service, and so on. In fact, in 2004, the whole island nation of Jamaica was disconnected from the world by Hurricane Ivan. First a cable break occurred from wave action in the shallows off Kingston. The country was still connected via a fiber-optic cable to the west through the Cayman Islands. But the Cayman Islands were the next target downrange . . . dead in the sights of Ivan. A redundant cross-island connection there to a major Caribbean regional cable system was then severed, isolating Jamaica from the world for most of a week, aside from some low-capacity satellite connections.

So failures are much more common than most of us would assume or even imagine. And yet backbone fiber-optic transport networks are now absolutely crucial to society. So how do services survive the failure of their underlying physical elements? Certain approaches to the problem are what this book is about and these authors are the sort of “dream team” to write on the topic. Designing and operating networks in a way that services can recover from failures almost instantly is a key aspect of transport networks. Being based in Canada, I can report that here it is seen as so vital and essential an infrastructure that governmental organizations have identified the telecommunications system as one of Canada’s ten most critical infrastructures and are keenly funding research to “produce new science-based knowledge and practices to better assess, manage, and mitigate risks to from critical infrastructure.” Similar developments and recognition of the telecommunication transport network as critical national infrastructures are well established in the USA and Europe.

This brings us to the timing for this book, and the perfect suitability of these authors to the topic. Bouillet, Ellinas, Labourdette and Ramamurthy were all at Tellium during a phase of history in this field, where remarkable vision, talent, timing and technological mastery combined to breathe real life into one of my own long-held visions, that of distributed mesh-based “selfhealing networks.” Tellium was the provider of the world’s first in-service, intelligent optical switch, tested and operated in a nationwide 45-node network by Dynegy’s telecommunications subsidiary. The Aurora Optical Switch was a 512-port OEO switch of STS-48 (2.5 Gbps) granularity that realized greater network capacity, reliability, and capital efficiencies than network operators had previously seen. Interestingly, during its operating life the Dynegy’s network was actually “reoptimized” twice while in service as described in Chapter 10 of the book. Distributed mesh restoration ability was part of the advanced operational capabilities of optical networks built with Tellium cross-connects at a time when some larger vendors were still deadlocked in the ring versus mesh debate. But, at least in my view, the advantages of mesh-oriented operation and survivability were abundantly clear by then and Tellium led the way to practical realization of these potentials. And these authors were at the center of it all. This central Tellium connection between the authors, and their other past experiences mean they write with the authority of technical experience and practical awareness of the issues involved. But the material in the book is more general than just the Tellium experience. An example of another large operational deployment of a distributed mesh-based selfhealing network was the AT&T one using the Ciena CoreDirector platform, switching at STS-1 granularity.

Eric Bouillet worked at Tellium on the design of optical networks and optimization of lightpath provisioning and fault restoration algorithms; and before that in the Mathematical Sciences Research Center in Bell Labs/Lucent Technologies on routing and optimizations of telecommunication networks. Georgios Ellinas was a senior network architect at Tellium Inc. In this role, he worked on lightpath provisioning and fault restoration algorithms in optical mesh networks, and the architecture design of another Tellium development project, that of a MEMS-based all-optical (OOO) switch. George also served as a senior research scientist in Telcordia Technologies’ (formerly Bellcore) Optical Networking Research Group. George performed research for the Optical Networks Technology Consortium (ONTC), Multiwavelength Optical Networking (MONET) and Next Generation Internet (NGI) projects. Jean-Francois Labourdette, currently with Verizon Business, was Manager of System Engineering at Tellium, responsible for network element and network management system engineering activities. When he first joined Tellium, he was Manager of Network Routing and Design, responsible for Tellium’s routing architecture and algorithms, network dimensioning, and customer network design activities. Previously, he was a Manager of Data Services Globalization Planning at AT&T and before that a System Engineer in the routing planning group, working on dynamic call routing for AT&T’s switched network and facility routing and rearrangement for the AT&T transport network. Ramu Ramamurthy has worked in software and systems engineering at Cisco Systems, Ciena Corp, Tellium, Bellcore, and Bay Networks.

Of the only three or four books available to date on the topic of survivable transport network operation and design, I recommend this title as a must-have for network planners, researchers and graduate students in Optical Networking.

Wayne D. Grover, P.Eng, Ph.D, IEEE Fellow, NSERC Steacie Fellow, FEIC Professor, Department of Electrical and Computer Engineering, University of Alberta, Chief Scientist (Network Systems Research), TRLabs, Edmonton, Alberta, Canada

Notes on sources

Interested readers can find information on some of the typical failures cited from CANARIE, “About CA∗net 4,” available on-line: www.canarie.ca/canet4/index.html, CANARIE, “CA∗net 4 Outage Reports.” See also D. Crawford, “Fiber Optic Cable Dig-ups: Causes and Cures,” Network Reliability: A Report to the Nation–Compendium of Technical Papers, National Engineering Consortium, Chicago, June 1993. FCC Outage reports are also available at Federal Communication Commission. For example, one mentioned is “FCC Outage Report 02–026,” FCC Office of Engineering and Technology Outage Reports, February 2002. The Canadian initiative mentioned on critical infrastructure research is the Natural Sciences and Engineering Research Council of Canada, “Joint Infrastructure Interdependencies Research Program (JIIRP),” accessed 8 November 2004, www.nserc.gc.ca/programs/jiirp_e.htm, March 2004. The Dynegy network deployment mentioned in the Foreword is described further in the book’s own references [CHAR02] ([65]), [CHAR03] ([66]). The MEMS-based all-optical (OOO) switch development project at Tellium is described in [ELLI03] ([108]). AT&T’s STS-1 managed Selfhealing mesh network is described in [CORT02] ([87]) and [RANG02] ([259]). (The latter references are referred to in the form they appear in the book’s bibliography.)