100Base-SX and fiber to the desk
 
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Fiber-optic equipment vendors have been pushing the idea of fiber-to-the-desktop for years, but the idea has failed to take hold because of the cost and the broad installed base of copper wiring.
In response, the vendors are trying to make fiber-to-the-desktop easier to swallow. The latest effort is the proposed standard 100Base-SX.
Fiber versions of Fast Ethernet already exist, but the SX version would add a dimension of flexibility that is lacking today. The existing 100Base-FX uses a 1300 nm LED for transmissions over multimode fiber, while the slower 10Base-FL uses 850 nm. Because of this difference, it was impossible to build devices that could accommodate 10M and 100M bit/sec, and users had to install all new equipment to upgrade from one to the other.
The proposed SX standard uses an 850 nm LED, so the optoelectronics would be compatible with the 10M bit/sec fiber standard and would make it possible to deliver 10/100M bit/sec fiber devices. 100Base-SX can't transmit as far as 100Base-FX, however. SX reaches 300 m, as opposed to the 2 km of FX.
But if you are considering fiber-to-the-desktop, 300 m ought to be more than adequate.
