It is without saying that 40/100 GbE is coming. The existing cabling solution and optical transceivers can not satisfy the trend, thus data center managers are striving to determine which fiber optic links will support 10 GbE today while future proofing the best, most effective migration path to 40/100 GbE tomorrow.

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Fiberstore (FS.COM) | Choose 24-fiber for 40/100G Migration
It is without saying that 40/100 GbE is coming. The existing cabling solution and optical transceivers
can not satisfy the trend, thus data center managers are striving to determine which fiber optic links
will support 10 GbE today while future proofing the best, most effective migration path to 40/100
GbE tomorrow. Some recommend that the use of 12-fiber multimode trunk cables can provide the
best migration path to 40 and 100 GbE. While others confirm that 24-fiber trunk cables with
24-fiber MPOs on both ends is a better standards-based transition path. It all comes down to a brief
comparison of these two cables over investment and reduced future operating and capital expense.
24-fiber Solution
The use of 24-fiber trunk cables between switch panels and equipment is a common-sense
approach, but people may not be familiar with this optic scenario. In fact, a 24-fiber trunk cable is
used to connect from the back of the switch panel to the equipment distribution area. For 10 GbE
applications, each of the 24 fibers can be used to transmit 10 Gbps, for a total of 12 links. For 40
GbE applications, which requires 8 fibers (4 transmitting and 4 receiving), a 24-fiber trunk cable
provides a total of three 40 GbE links. For 100 GbE, which requires 20 fibers (10 transmitting and 10
receiving), a 24-fiber trunk cable provides a single 100 GbE link as shown in Figure 1.
Maximum Fiber Utilization
Choose 24-fiber for
40/100G Migration

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Fiberstore (FS.COM) | Choose 24-fiber for 40/100G Migration
As noted before, 40 GbE uses eight fibers of a 12-fiber MPO connector, leaving four fibers unused.
When using a 12-fiber trunk cable, three 40 GbE links using three separate 12-fiber trunk cables
would result in a total of 12 unused fibers, or four fibers unused for each trunk. But with the use of
24-fiber trunk cables, data center managers actually get to use all the fiber and leverage their
complete investment. Running three 40 GbE links over a single 24-fiber trunk cable uses all 24 fibers
of the trunk cable. Obviously, 24-fiber is more appropriate for 40/100G migration.
Increased Fiber Density
Because 24-fiber MPO connectors offer a small footprint, they can ultimately provide increased
density in fiber panels at the switch location. With today’s large core switches occupying upwards of
1/3 of an entire rack, density in fiber switch panels is critical. Hydra cables feature a single 24-fiber
MPO connector on one end and either 12 duplex LC connectors on the other end for 10 GbE
applications, 12-fiber MPO connectors for 40 GbE or a 24-fiber MPO connector for 100 GbE. With a
single 1RU fiber panel able to provide a total of 32 MPO adaptors, the density for 10 GbE
applications is 384 ports in a 1RU (duplex LC connectors) and 96 40 GbE ports in a 1 RU (12-fiber
MPOs). Figure 2 shows a 12-fiber MTP trunk cable with MTP/APC connector on both ends largely
improves the performance for 40G/100G fiber links.
Reduced Cable Congestion
Cable congestion is one of the biggest problems in the data center because it will make cable
management more difficult and impede proper airflow needed to maintain efficient cooling and
subsequent energy efficiency. In fact, a 24-fiber trunk cable are only appreciably larger than 12-fiber
trunk cables in diameter. That means the 24-fiber trunk cables provide twice the amount of fiber in
less than 21% more space. For a 40 GbE application, it takes three 12-fiber trunk cables to provide
the same number of links as a single 24-fiber trunk cable—or about 1-1/2 times more pathway
space.
Cost-effective Migration Path
As 24-fiber trunk cables can effectively support all three applications shown in Figure 3, there is no

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Fiberstore (FS.COM) | Choose 24-fiber for 40/100G Migration
need to recable the pathways from the back of the switch panel to the equipment distribution area.
That means that data center managers can easily migrate to higher speeds with all of that cabling
remains permanent and untouched. With 24-fiber trunk cables offer guaranteed performance for
10, 40 and 100 GbE, upgrading the cabling infrastructure is as simple as upgrading the hydra cables
or cassettes and patch cords to the equipment.
Conclusion
With guaranteed support for all three applications, the ability to use all the fiber deployed, reduced
cable congestion and higher port density in fiber panels, and an easy migration scheme, 24-fiber
trunk cables offers lower future capital and operating expense. Fiberstore supplies 12, 24, 48, 72, 96
and 144 fiber core constructions with OM1, OM2, OM3 or OM4 fiber trunk cable, these trunk cable
assemblies are composed of high quality LSZH jacketed fiber optic cables, connecting equipment in
racks to MTP/MPO backbone cables. 40G QSFP+ optical transceivers like QSFP-40G-LR4-S are also
provided. If you are interested in any of our products, please contact us directly.

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Fiberstore (FS.COM) | Choose 24-fiber for 40/100G Migration
Contact Us
Manufacturing R & D (China)
Eastern Side, Second Floor, Science &
Technology Park, No.6, Keyuan Road,
Nanshan District, Shenzhen 518057,
China
Tel: +86 (755) 8300 3611
Fax: +86 (755) 8326 9395
Email: sales@fs.com
APAC Office (Hong Kong)
1220 Tung Chun Commercial Centre,
438-444 Shanghai Street, Kowloon,
Hong Kong
Tel: +852 81763606
Fax: +852 81763606
Email: sales@fs.com
North America (United States)
331 Andover Park East Ste330, Tukwila,
WA 98188,United States
Tel: +1-425-226-2035
Fax: +1-253-246-7881
Email: sales@fs.com
London Office (United Kingdom)
Third Floor 207 Regent Street, London,
W1B 3HH, United Kingdom
Tel: +44 2081441980
Notice: This document is for informational purposes only and does not set forth any warranty, expressed or
implied, concerning any equipment, equipment features, or service offered or to be offered by Fiberstore.
Fiberstore reserves the right to make changes to this document at any time, without notice, and assumes no
responsibility for its use. This information document describes features that may not be currently available.
Contact a Fiberstore sales team for information on feature and product availability.
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