Ethernet Switches

Preface

Ethernet switches, also known as bridges, are basic building blocks of networks, and are so commonly used that you may not give them a second thought. It’s possible to build networks without knowing very much about how switches work. However, when you build larger network systems, it helps to understand both what goes on inside a switch and how the standards make it possible for switches to work together.

Ethernet is used to build networks from small to large, and from simple to complex. Ethernet connects your home computers and other household devices; switches for home networks are typically small, low cost, and simple. Ethernet also connects the Internet worldwide, and switches for Internet Service Providers are large, high cost, and complex.

Campus and enterprise networks often use a mix of switches: simpler and lower-cost switches are usually found inside wiring closets and used to connect devices on a given floor of a building; larger and higher-cost switches are found in the core of the network and are used to connect all the building switches together into a larger network system. Data center networks have their own special requirements, and typically include high performance switches that can be connected in ways that provide highly resilient networks.

According to industry estimates, the worldwide market for enterprise switches recorded revenues of over $5 billion per quarter in 2012, with total revenues exceeding $20 billion for the year. For the second quarter of ...