is essential to follow correct procedures in administration of fiber optic
patch cords to achieve optimum performance and reliability. The principles of good
management for fiber optic cords are similar to those for twisted pair
however, there are special considerations with optical fiber and extra care is
needed in some areas. Applying best practices at every stage will also minimize
costs related to moves, adds and changes (MACs).
practices in fiber patch cord management can be divided into four parts:
activities (i.e., MACs) are initiated with a change request. The change request
must contain all necessary information to begin the planning process. Once a
request form is received, search the records to be sure of the circuit path.
changes or additions made since your cabling infrastructure was installed
should also be documented. If the records are stored in a database, such as an Automated Infrastructure Management (AIM) system, a different
screen can be displayed for each user. This screen should supply you with the
information you need, including the riser and horizontal fiber pairs serving
the particular area and the locations of available fiber.
CLICK TO TWEET: Managing fiber patch cords can be divided into four parts. Read James Donovan's blog to learn more.
Check Design Guidelines and Match Cords
sure you know the specifications and design of your fiber cabling. Ensure you
have patch cords matched to the installed cabling, since optical fiber cords of
different types should not be mixed.
first step in choosing a cord of the correct length is to determine the best
route between its points of connection. Having established the best route for
the cord, find the required length by adding the horizontal and vertical
selecting a cord to make a cross connection, avoid excessive slack and provide
a neat appearance. Tight or stretched cords will pull on connectors, and too
much slack complicates cord management making the panel more difficult to work
you have cords of the right length available and that panels are fitted with
correct cable management accessories. At the optical patch panel, route patch
cords equally toward both sides of the vertical cable management channels to
prevent overloading one side.
care not to mix up cords of different optical core diameters. Additionally,
cords must be of the same or higher bandwidth as the behind-the-wall cabling.
System performance regarding distances cannot be guaranteed if lower rated
patch cords are used. Color-coding of connectors for different fiber standards
make it easy to avoid confusion.
patch cords must use the same core diameter as the trunk cable. A large
attenuation penalty will occur when using a 62.5-μm patch cord with a 50-μm
trunk fiber cable or vice versa. Single mode fiber patch cords should use fiber
with the same Mode Field Diameter as the trunk cable fiber.
Factory-terminated vs. Field-polished
cords guarantee fiber patches with optimum performance. Field polished cords
are likely to deliver lower performance and variable quality.
Fiber Safety Precautions and
lasers that carry information through fiber cables may cause irreparable damage
to the retina. Always avoid looking directly into an energized optical fiber,
and never attach a microscope or other magnifying device to an energized
optical fiber. Always wear appropriate eye protection and ensure that unused
ports are covered.
minimize disconnect time, do as much preparation as possible before performing
administrative activities. Locate the ports that must be connected or
reconnected. Ensure technicians have clear information on what they need to do,
including labeling information for the ports involved.
is essential to ensure cords are of the right type and quality, and that they
are clean and in good condition.
patch cords should be inspected for physical damage including:
marks from bending on the sheath
of fibers from the connector
or scratches on fiber end in the connector using a fiber examination microscope
is vital in fiber optic connections so special care is needed with connector
work on a panel is started, it should be completed without delay using best
practice at each stage. Kinks, snags, pinches and poor contacts can
dramatically reduce the performance of a fiber patch cord. The following
factors are important in avoiding these problems.
minimum bend radius for optical fiber patch cords varies with cord diameter and
should be verified before use. Exceeding the bend radius can result in significant
additional loss and adverse impact on channel performance.
Cord Pulling and Stress
careful not to use excessive force during the patching process. This can stress
cords and connectors, reducing their performance. If you need to use force in
pulling a cord, something is wrong. Find the problem and fix it before
and tying cords gives the panel a neat appearance but tight bundling increases
the risk of pinching. Do not tighten ties beyond the point where individual
cords can rotate freely. Use only products manufactured for this purpose and
consider the use of products that can be re-used without the use of tools such
as “hook and loop” strapping.
Routing Cords Through Cable Pathways
the existing cord is the right length, it may be possible to re-use it. If this
is the case, remove the cord completely and re-run it in through the cable
pathways. This is the only sure way to ensure there are no tangles, kinks or
strains in the cord.
Final Visual Inspection and Panel Closure
must be right first time since mistakes can cause costly disruption and
re-work. The time taken to make a final visual check on connections is a good
investment. When patch panels are mounted in enclosures, ensure these are
securely closed and, where necessary, locked, making sure that cord slack is
not snagged or pinched by the doors.
final step is to update the documentation to the as-built configuration and
close the work order associated with the completed change request. Using an AIM
system will automate much of this activity and aid the patching process.
you are looking for a free course, the CommScope Infrastructure Academy offers
the Best Practice for
Patch Cord Management (WR9301) course. It is a free instructional video that
looks at the best practices and recommendations for planning, preparing
connections in network infrastructure.