Information Technology Reference
In-Depth Information
Copper to Fiber Conversion
It is practically impossible to entirely avoid the use of copper interfaces. Many types
of equipment, such as printers and routers, may offer only copper interface options.
It may be possible to use switch/hubs with both types of connections. The desktop
workstations and servers are connected normally via fiber, and the incompatible
equipment is connected to a switch/hub with an appropriate copper interface.
In cases where the hub-conversion method is impractical, you can simply use a
fiber to copper converter. You have several options on fiber to copper conversion.
At 10 Mbps Ethernet, you can convert from fiber to the AUI, coax, or 10Base-T
connections. The AUI is convenient because the interface includes a power source
for a transceiver, which can be used to power the converter. In all other cases, you
can expect to use one of the boxy wall-plug transformers and a power cord to the
converter.
Pay particular attention to the type of fiber-optic interface on your converter.
The 100 Mbps fiber-optic interface is now available in either FX or SX versions, and
the wavelengths are totally different. Likewise, 10BaseFL and -FB are available,
although the FB variety is rare. Gigabit Ethernet fiber interfaces are likewise avail-
able in several varieties of wavelength and mode, so pay attention to the needs of
your equipment and/or fiber cable when making a choice.
In addition to the copper to fiber converters, fiber mode converters are avail-
able (Fig. 11.9). Because of the common connectors, nothing physically prevents the
interconnection of single-mode and multimode fibers. However, the connection will
cause an excessive transmission loss if the optical direction is from multimode to
single-mode. There is still an unexpected loss from single-mode to multimode, but
FIGURE 11.9
A fiber-optic mode converter. (Courtesy of Transition Networks, Inc.)
