Dirty Endface (Oils)
FIGURE 9: Comparison of most common dirt and debris found on connector endfaces.
Connector Cleaning and Best Practices
It can be argued that the modern data center relies on
a connector or rather a million connectors. They might be
factory installed or they might be spliced on. Either way,
the technician or installer should worry about whether
the connectors are clean and undamaged. It is reasonable
to expect that factory-installed connectors are undamaged
but expecting them to be clean is a different situation.
As one industry expert said, “Dust caps are aptly named…
they hold dust.” If the connector is not clean, then it is
not going to deliver the performance required in today’s
high-speed networks. Have you ever tried driving 100
mph with a dirty windshield? It does not end well. Trying
to drive 100 Gb through a dirty connector is no different.
It is estimated that over 80 percent of network turn-up
failures are due to dirty or damaged connectors.
14 I ICT TODAY
What is worse is that even if the dirt or damage did
not impact the connection on Day 1, perhaps due to
10 GbE transmission, there is the possibility of what
may happen on Day 1001 when there is an upgrade to
25 GbE transmission. If the world were a perfect place
with perfect conditions, product, and staff, technicians
and installers would not need to clean, inspect, and test.
Even in a tightly environmentally controlled data center,
there are plenty of small particles, such as dust and
pollen (Figure 9) that can block the light on an 8
to 10 μm optical core endface (Figure 10).
The IEC defines a clean connector as having no
scratches and no defects (e.g., dirt, pollen) in the core.
There cannot even be any scratches greater than 3 μm
or defects greater than 5 μm in the cladding. It is important
to remember that any piece of debris anywhere on
Coating
Cladding
— 150 Microns
25 Microns
Average Human Hair
Lint, Particles Visible to the Naked Eye
10 Microns Heavy Dust, Lint, Fertilizer, Pollen
5-10 Microns Average Dust, Plant Spores, Mold
1-5 Microns Bacteria, Light Dust, Animal Dander
0.3-1 Microns Bacteria, Tobacco and Cooking Smoke, Metallic Fumes
FIGURE 10: Fiber-endface cross section.
Clean Endface
(Core colored green - note size)