Information Technology Reference
In-Depth Information
The SFF connector types offer so many varieties that an abundance of adapter
cables will be made available. In addition to adaptation to the legacy connectors
(which would include the 568SC), cords must be available to transition between each
of the popular SFF types. It would be wise to try to minimize the number of combi-
nations of connectors by evaluating the types of connectors that are generally avail-
able on the networking equipment you will be using. The higher-density devices will
gravitate toward one of the SFF connectors. Thus, hubs and switches in the TR will
tend to use an SFF connector to achieve maximum connection density. On the work-
station NIC, the connector density is not an issue, so the decision to use an SFF con-
nector will be at the manufacturer's discretion. Although there is a battle among
manufacturers to control the fiber connector type in the horizontal cable plant, it is
not at all clear that network managers will make equipment decisions solely on the
basis of connector type. Since horizontal runs rarely terminate directly in the network
equipment, an adapter cord can easily be used, no matter what connector is needed.
As the number and types of fiber-optic connectors diverge, proper installer
training is very important. Many of the connector designs are distinctly nonintuitive
with respect to assembly. In order for the connector to operate according to its spec-
ifications, all of the installation practices must be controlled right down to the mil-
limeter. Connector designs are very different from one manufacturer to another.
Installers should be trained on the connector brand they are installing, and network
managers should require training and certification of installers and contractors.
While this is not rocket science, it is certainly not simple, and the quality and
longevity of your fiber cable plant may well depend on the quality and consistency
of the installation.
Fiber-optic cable installation requirements call for the storage of extra fiber at
the points of termination. The reason for this is simply to allow for future connec-
tor changes and for the re-termination of the fiber due to potential breaks after
installation. The extra fiber must be stored in a manner that protects it from dam-
age. At the work area outlet, the cable could theoretically be coiled up in the
recessed outlet box, if one is used. However, LAN wiring is often done with outlet
rings that are totally open to the wall space, as illustrated in Chapter 6. A safe alter-
native is to use one of the special fiber outlet boxes that mount to the surface of the
wall and contain a means for storing and protecting the fiber strands, as shown in
Fig. 11.12, as well as in Chapter 6.
Fiber-Optic Testing
Once installed, fiber must be tested to determine proper operation. Simple connec-
tivity may be determined by a simple source and detector arrangement, much like
