Information Technology Reference
In-Depth Information
FIGURE 6.17
Examples of small form factor (SFF) connectors: From left to right, the LC, the MT-RJ, the Opti-
Flex, and the WF-45.
Additional information regarding fiber connectors, including several of the SFF
types, is given in Chapter 11 in Table 11.2.
Which Fiber Connector?
The advent of fiber-optic cable communications systems has seen the progressive intro-
duction of a wide variety of optical connectors. The dominant types that have been used
for LAN connections are the SMA, the ST, and most recently the SC. Now, the landscape
is littered with innovative new SFF connectors, because of liberalized TIA-568-C rules.
Which connector should you use?
All of the connectors mentioned provide close fiber alignment, reliability, and some
measure of industry standardization. However, the SMA and the ST are not easily adapt-
able to a duplex arrangement so that two fiber connections can be made at the same
time. Both of these connector styles must be used individually, because they require the
twisting of a threaded or a bayonetlocking ring to secure the connectors to the mating
jack. The SC connector, on the other hand, uses a push-on/pull-off mechanism that
allows the two individual connectors to be attached together and connected or discon-
nected simultaneously. In addition, the new SFF connectors often use some sort of clip-
in mechanism that retains the plug-jack mating under considerable physical loads.
The SC connector, mounted as a duplex unit, was originally selected as the rec-
ommended connector in TIA/EIA-568-A. However, this “568SC” has a 12.7-mm
