Introduction

Fibre Channel technology is over a decade old. How successful has it been?

Here is an illustration. The first edition of this book included a section called The Unification of LAN and Channel technologies, which described how Fibre Channel would be part of a trend towards convergence between LANs and channels. LANs (Local Area Networks) are used for computer-to-computer communications, and channels are high-efficiency, high-performance links between computers and their long-term storage devices (disk and tape drives), and other I/O devices.

Since then, the prediction has come true, in three quite different ways.

• Most important has been the introduction and widespread use of the term Storage Area Network, or SAN, describing a network which is highly optimized for transporting traffic between servers and storage devices.

• At the physical layer, the LAN and Fibre Channel technologies have become nearly identical Gigabit Ethernet and Fibre Channel share common signaling and data encoding mechanisms, and the future 10 Gb/s Ethernet and Fibre Channel are expected to share nearly the same data rate.

• The management methods for Fibre Channel SANs have steadily approached the traditional methods used for LAN management, although the current level of management effort required for Fibre Channel SANs is still higher than for LANs.

Interestingly, however, although the LAN and SAN types of computer data communications have converged at a technology level, they have so far stayed quite different in how they are used and how they are managed. That is, systems are usually built with...