Metro Area Networking
Detailing the technological challenges and opportunities in a lucid, humorous prose, this book lays bare the tricks and traps awaiting service providers in the metro area space.
TABLE OF CONTENTS Metro Area Networking
One Step Up: Gigabit Ethernet (1000BaseX)
1000BaseX, otherwise known as Gigabit Ethernet, is a relatively new arrival on the scene that has turned the LAN world on its ear and had an extraordinary impact on the metro world. Suddenly, corporate LANs are no longer hobbled bytheir glacially slow 10 Mbps networks or even their all-too-slow 100 Mbps LANs. As with the Fast Ethernet series, Gigabit Ethernet standards actually define a family of standards, described later.
Interestingly, these standards are based on physical-layer specifications adapted from the ANSI X3.230-1994 standard for Fibre Channel, a high-speed interface specification that has long been used for storage applications. By adopting the existing Fibre Channel specifications, 1000BaseX products found the market significantly easier to penetrate. It is important, however, that 1000BaseT does not use the Fibre Channel physical layer specifications and is not part of the 1000BaseX family of standards. 1000BaseT is described later in this part.
1000BaseLX
1000BaseLX is a fascinating standard, and the technologies that underlie it are equally interesting. The L in LX stands for long, because it relies on long wavelength lasers to transmit significant amounts of data over long-haul fiber. The lasers specified by the standard operate in the 1270- to 1355-nanometer range, and both single and multimode fiber are supported. Although long-wavelength lasers are more expensive than short-wavelength devices, they can transmit reliably over longer distances.
1000BaseSX
The antithesis of 1000BaseLX, 1000BaseSX (short) relies on short-wavelength lasers operating in the 770- to 860-nanometer range to transmit data over...
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