Ethernet: The Definitive Guide

Chapter 12. Gigabit Ethernet Fiber OpticMedia System (1000BASE-X)

The specifications for the 1000BASE-X system were developed in the 802.3z supplement to the IEEE standard. 1000BASE-X is a collective identifier for three media segments: two fiber optic segments and a short copper jumper. Of these three, the fiber optic segments are widely used, while the short copper jumper has not been adopted by the marketplace. Therefore, this chapter describes the two fiber optic segments in detail, with coverage of the short copper jumper included for completeness. The two fiber optic segments consist of a 1000BASE-SX ( short wavelength) segment and a 1000BASE-LX (long wavelength) segment. The third segment type is called the 1000BASE-CX short copper jumper.

The 1000BASE-X media system is based on specifications first published in the ANSI X3T11 Fibre Channel standard. Fibre Channel is a high-speed network technology that was developed to support bulk data applications such as linking file servers and providing high speed image transport for video editing. The 1000BASE-X standard adapted the signal encoding and physical medium signaling from the Fibre Channel standard, with the only major change being an increase in the data rate from 800 Mbps to 1000 Mbps.

The first part of this chapter provides a brief look at 1000BASE-X components and signaling, followed by a more detailed look at the three 1000BASE-X media segments, with an emphasis on the widely used fiber optic segments.

1000BASE-X ...