QUIZ BY JIM HAYES
1. An experienced installer decided to field-install single-mode connectors on short cables in a data center using
familiar multimode termination techniques. The resulting
terminations passed all tests except for _________.
A. Insertion loss
B. Optical time-domain reflectometer (OTDR) loss
D. Fiber retention
2. The first tech testing these single-mode cables found all of the
cables failed with about 20 decibels loss because _________.
A. They were improperly polished
B. They had not been properly cleaned
C. The tech used multimode, fiber-test jumpers
D. All of the mating adapters were faulty
3. The second tech testing these same short, 50–70-meter
(m) cables used an unfamiliar OTDR that could not resolve
these very short cables properly because of the OTDR’s
4. The third tech finally found the problem with these
cables by _________.
A. Setting the OTDR to the shortest pulse width
B. Using longer launch and receive cables
C. Inspecting and cleaning all of the
D. All of the above
5. Connecting a new 10-gigabit (Gb) ethernet LAN to the
single-mode fiber optic backbone, an IT tech grabbed
some old orange-cable jumpers off of a rack and plugged
everything together. The network _________.
A. Worked fine
B. Failed to operate because of mismatched fiber losses
C. Had high bit-error rates caused by
D. Couldn’t connect because some fiber jumpers
broke while hanging on a rack
6. After finding the proper jumper cables to connect the
switches in the data center, the equipment showed high
bit error rates because of _________.
A. Too much loss
B. Too short cables with too little loss
C. Connector reflectance
D. Bandwidth limitations
7. One set of 10-Gb switches was upgraded to 100 Gb on
available OM4 fiber with duplex connections using new
equipment with _________.
A. 850–950 nanometer (nm) wavelength multiplexing
B. Conversion to 1,310-nm lasers
C. Time-spatial multiplexing
D. Passive splitters
8. On a row of servers in the data center, it was decided to use
Cat 8 cables at 40 Gb. The cable lengths ran from 5–55 m,
easily within Cat 8 specs for 40 Gb.
9. After testing Cat 8 cables, the data center owner went
back to an all-fiber network because Cat 8 _________.
A. Wasn’t less expensive
B. Used too much power
C. Did not have sufficient length capability
D. All of the above
10. Nearing the end of an install of Cat 6a cable, a tech ran
out of Cat 6a jacks but had Cat 5e ones, which he used.
When tested, those runs _________.
A. Passed all Cat 6a tests
B. Just met Cat 6 test requirements
C. Only performed at Cat 5e levels
D. Could not be tested
HA YES is a VDV writer and educator and the president of the Fiber Optic Association. Find him at
Data Center Cabling: What Could Possibly Go Wrong?
Sometimes, things go wrong. Sometimes, it takes a few tries to do it right, such as in this
(hypothetical) data center installation. ANSWERS ARE ON PAGE 103. TO TAKE THE QUIZ ELECTRONICALLY,