DeCusatis - Handbook of fiber optic data communication a practical guide to optical networking

In previous editions of this Handbook, I have tried to summarize the importance of optical networking to the data communication field with the following bit of poetry:

SONET

When I consider how the light is bent

By fibers glassy in this Web World Wide,

Tera- and Peta-, the bits fly by

Are they from Snell and Maxwell sent

Or through more base physics, which the Maker presents

(lambdas of God?) or might He come to chide

Doth God require more bandwidth, light denied?

Consultants may ask; but Engineers to prevent

that murmur, soon reply The Fortune e-500 do not need

mere light alone, nor its interconnect; who requests

this data, if not clients surfing the Web? Their state

is processing, a billion MIPS or CPU cycles at giga-speed.

Without fiber optic links that never rest,

The servers also only stand and wait.

C. DeCusatis, with sincere apologies to Milton

Of course, I am certainly not the only network engineer to be inspired by classic literature. Those of you who prefer Joyce Kilmer (http://www.poetry-archive.com/k/trees.html) to Milton might enjoy the following well-known piece, crafted by Radia Perlman while she was inventing the Spanning Tree Protocol (https://www.cs.washington.edu/education/courses/461/08wi/lectures/p44-perlman.pdf), which you can also hear set to music online with Ms. Perlman on piano and her daughter on vocals (http://www.youtube.com/watch?v=iE_AbM8ZykI).

Algorhyme

I think that I shall never see

A graph more lovely than a tree.

A tree whose crucial property

Is loop-free connectivity.

A tree that must be sure to span

So packets can reach every LAN.

First, the root must be selected.

By ID, it is elected.

Least-cost paths from root are traced.

In the tree, these paths are placed.

A mesh is made by folks like me,

Then bridges find a spanning tree.

The radical changes currently taking place in data networking are perhaps reflected in another poem by Radias son, Ray Perlner, who wrote this tribute to the TRILL protocol:

Algorhyme V2

I hope that we shall one day see

A graph more lovely than a tree.

A graph to boost efficiency

While still configuration-free.

A network where RBridges can

Route packets to their target LAN.

The paths they find, to our elation,

Are least cost paths to destination!

With packet hop counts we now see,

The network need not be loop-free!

RBridges work transparently,

Without a common spanning tree.

The potential replacement of spanning tree protocols (whether by TRILL or other options) is only one of the many changes in this field that led us to believe the time was right to once again update this Handbook. This is a very interesting time to be a network engineer, as the field experiences perhaps its greatest upheavals since Metcalf first introduced the basic principles of Ethernet. Since the first edition of this book was published over 10 years ago, I have tried to continually incorporate feedback and comments from readers to improve the book and ensure that it continues to provide a single, indispensable reference for the optical data communication field. You will still find a single reference for all the leading data center networking protocols and technologies, as well as many new chapters dealing with issues that did not exist when the last edition was published (including the TRILL protocol mentioned earlier). A series of all new case studies discuss real-world applications of this technology. It has become apparent that network virtualization is the next big frontier, and we are just beginning to see the full potential of data center networkingapplication aware, distance independent, infinitely scalable, user-centric networks that catalyze real-time global computing, advanced streaming multimedia, distance learning, telemedicine, and a host of other applications. We hope that those who build and use these networks will benefit in some measure from this book.

An undertaking such as this would not be possible without the concerted efforts of many contributing authors and a supportive staff at the publisher, to all of whom I extend my deepest gratitude. As always, this book is dedicated to my mother and father, who first helped me see the wonder in the world; to the memory of my godmother Isabel; and to my wife, Carolyn, and my daughters Anne and Rebecca, without whom this work would not have been possible.

Dr. Casimer DeCusatis

Editor, Poughkeepsie, New York

December 2012