Completion
Complete each
statement.
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1.
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This is The FOA Online Design Self-Study Program Case Study
No. 7, Data Center.
This exercise covers the design of a A Data Center. A data center is
being built to expand a corporate network and support Internet servers for a large audience.
Connections are planned to use 10G Ethernet but upgrades to 40 or 100 GbE are expected in the future.
Besides providing adequate capacity, reducing energy consumption is important, leading to a choice of
fiber over copper for its lower power requirements.
The servers will be
using a "top of rack" design. Cabling is planned to be installed in underfloor wire
tray, however, alternatives may be considered. The permanently installed cables will be terminated in
patch panels and short patchcords used to connect the servers.
Please enter your
name, CFOT/Membership number and date to begin this exercise.
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Multiple
Choice
Identify the choice
that best completes the statement or answers the question.
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2.
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The servers will be in a "top of rack" design
configuration. What kinds of cables are appropriate for use in the short 10G Ethernet connections of
the switch to the servers in the rack?
a. | UTP Cat 6A | b. | MM fiber,
OM3/4 | c. | Coax CX-4 | d. | Any of
these |
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3.
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The system will be transmitting Ethernet at 10 Gb/s speeds
over relatively short lengths of multimode fiber between switches.
What will be the wavelength
used for transmission?
a. | 1310 nm | b. | 850
nm | c. | 1550 nm | d. | 650
nm |
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4.
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What is the minimum performance grade of multimode
fibers appropriate for this installation, assuming links are more than 100m?
OM1, OM2, OM3 or
OM4 ?
a. | Any of these fibers will work | b. | Either OM3 or OM4 | c. | Either OM1 or
OM2 | d. | OM4 only |
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5.
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If the network is planned for upgrades to 40 or 100 Gb/s
using parallel transmission over multimode fibers, the same fibers can be used but what must be
included in the design plans?
a. | Better connectors | b. | Many additional fibers for parallel transmission | c. | Fibers with less delay variation | d. | Lower loss in the
link |
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6.
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If the network is planned for upgrades to 40 Gb/s using the
same multimode fibers, how many fibers must be included in the design plans?
a. | 2 fibers per link | b. | 4 fibers per link | c. | 8 fibers per
link | d. | 12 fibers per link |
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7.
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If the network is planned for upgrades to 100 Gb/s using the
same multimode fibers, how many fibers must be included in the design plans?
a. | 2 fibers per link | b. | 4 fibers per link | c. | 12 fibers per
link | d. | 24 fibers per link |
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8.
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If the network is planned for upgrades to 40 or 100
Gb/s but will use multimode transmission with VCSELs using wavelength-division multiplexing, how many
fibers must be included in the design plans?
a. | 2 fibers per link | b. | 4 fibers per link | c. | 12 fibers per
link | d. | 24 fibers per link |
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9.
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If the network is planned for upgrades to 40 or 100
Gb/s but will use singlemode transmission, how many fibers must be included in the design plans?
a. | 2 fibers per link | b. | 4 fibers per link | c. | 12 fibers per
link | d. | 24 fibers per link |
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10.
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The cable chosen for inside the buildings is a distribution
design to be laid in cable trays inside the office building so it must also be _____.
a. | Rated for pulling tension | b. | Rated for flame retardance | c. | Armored | d. | Water-blocked |
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11.
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The equipment for 10 GbE generally uses ___ connectors so it
may be more convenient to use them in the cable plant also.
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12.
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If a prefab cable plant with preterminated cables is used, the backbone cables
will propably use ________ connectors with parallel fiber connections.
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13.
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In order to ensure the system will work on the cable plant
being designed, it is necessary to have what information on the communication system intended for use
on the cable plant?
a. | Wavelength | b. | Transmitter min/max power
output | c. | Receiver min/max input powers | d. | All of the above |
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Typical Specifications
Provided for use as case
studies for design labs in FOA courses.
| Component
Specifications | | | | | Fiber
Loss | | | Multimode
at 850 nm | 3.0 dB/km (TIA 568: 3.5 dB/km) | | Multimode at 1300 nm | 1.0 dB/km (TIA 568: 1.5 dB/km) | | | | | Splice Loss | (TIA 568: 0.3 dB, all
types) | | | | | Connector Loss | (TIA 568: 0.75 dB, all types) | | Multimode, adhesive/polish | 0.3
dB | | Multimode,
prepolish/splice | 0.5 dB | | |
| Active Device and System Specifications | | | | | Digital Transceiver Specs1 | Power (dBm), T=transmit, R=receive | | 850 VCSEL (>1 Gb/s) | T: -3
to -9 dBm, R: 0 > -18 dBm | | |
Transmitter and receiver
specs do not reflect bandwidth penalties incurred by the length of the optical fiber and its
bandwidth performance. Link margin specifications for most standardized fiber optic networks are on
the FOA Tech Topics Site (http://www.thefoa.org/tech/Linkspec.htm). It should be used as a reference
for designers and for the courses.
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14.
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Using the information supplied above, assuming the component
specifications are per TIA standards, calculate the cable plant loss budget for the 50m link,
including the loss of the patchcords.
a. | 1.68 dB | b. | 1.35
dB | c. | 2.77 dB | d. | 3.18 |
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15.
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Using the information supplied above, assuming the component
specifications are typical values and connectors are adhesive/polish types, calculate the cable plant
loss budget for this link.
a. | 1.68 | b. | 1.35 | c. | 2.77 | d. | 3.1’,
]8 |
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Multiple
Response
Identify one or
more choices that best complete the statement or answer the question.
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16.
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What parameters should be tested and documented to confirm
proper installation?
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17.
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Testing of each fiber in the cable should be done as
follows:
(Choose all the correct answers)
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