nabling the carrier to place the transmission into an applicable SONET or SDH frame for Chapter Five transmission over a WAN. Of course, the distant location must also have an applicable fiber connection to the communications carrier to obtain a LAN-to-LAN transmission capability over a WAN at the LAN operat- ing rate. Now that we generally understand the use of fiber in Ethernet and Fast Ethernet environments, let's consider Gigabit Ethernet. Gigabit Ethernet The development of Gigabit Ethernet has a lengthy history that is beyond the scope of this book. However, there are certain milestones worth mentioning as well as the standards that define the technology. Similar to Ethernet and Fast Ethernet, the IEEE was responsible for standardizing Gigabit Ethernet. The basic Gigabit Ethernet standard is IEEE 802.3Z. This standard was ratified during June 1998 and defines the operation of Gigabit Ethernet over fiber. Another standard for the trans- mission of Gigabit Ethernet over copper-the IEEE 802.3ab specification, was delayed for several years and became finalized during 2000. Because the focus of this book is on the use of optical components, we will focus primarily on the 802.3z standard. Overview Gigabit Ethernet was developed to provide a migration path from 10- Mbit/s Ethernet and 100-Mbit/s Fast Ethernet to gigabit transmission. The primary use of the 1 Gbit/s rate of Gigabit Ethernet is to provide a back- bone network infrastructure for organizations running short of band- width. Because the per port cost of this technology exceeds that of Fast Ethernet by a factor of >10, it may be quite some time, if ever, before it is used for connecting desktop users. Thus, at the present time Gigabit Ether- net represents a technology oriented primarily toward connecting power stations to a network, such as servers and routers as well as connecting hubs in a tier, two applications that we will examine later in this section. Gigabit Ethernet was designed to comply as much as possible with previously developed 802.3 Ether