Foreword
Charles Darwin once said, “I have called this principle, by which each slight variation,
if useful, is preserved, by the term of Natural Selection.” This principle of evolution
applies to business as well as to nature. Individuals, companies, and industries evolve
and compete with one another in preparation for the future.
Back in 1998, a group of engineers decided to split from the mainstream and form a
new company, Juniper Networks. That company has evolved to create and acquire
many products over the last decade. While Darwin might have viewed this as an
evolutionary step in products, we view it as a competitive step.
Humankind differs from the rest of the animal kingdom not only because our instincts
go beyond the primal survival urge (a.k.a. Darwin’s “survival of the fittest”), but also
because of our intellect and capacity to improve. When one group splits off from
another, it does not necessarily sound the death knell for the original group. More likely,
the two groups will start taking steps to outdo one another. In other words, they
compete.
Those who are not directly involved in that competition can reap the benefits of the
intellectual sparring. We have observed many such competitive moves within the
routing industry over the years. Now, we are entering another such arena within
the switching side of our industry.
Evolution of the Bridging World
More than 20 years ago, Radia Perlman developed an interesting algorithm while
working for Digital Equipment Corporation. At the time, it was meant to solve an
irritating little problem brought on by the forced evolution of data networks. Although
networking in 1985 was significantly different than it is today, it’s amazing how some
of the basic building blocks have survived.
This book discusses some of those building blocks, both historically and with reference
to the present-day network infrastructure. For example, the Spanning Tree Protocol,
which was based on Perlman’s algorithm, is like one of the amino acids from which
today’s switching was created. (I’ve always despised biology, but it seems to fit here!)
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