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Cable Routing
The key consideration in cabling your datacenter is keeping airflow in mind. TIA-942 and
other datacenter standards advise horizontal and vertical cabling to be run accommodating
growth so that you don’t have to revisit cabling when your datacenter does grow (and it
will). There are a number of reasons to do this:
• Eliminating the adverse affects of removing floor tiles and decreasing static pressure
under raised floors during moves, adds, and changes (MAC) work
• Ensuring that pathways allow the flow of cold air in cold aisles to be unobstructed
by cabling
• Installing cabling to provide a baffle of sorts, channeling cool air into cold aisles
Unless the issue of cabling is addressed every time a datacenter is changed, cabling can
add to your cooling woes. A lot of older datacenters suffer because abandoned cabling
channels are left behind, creating an air dam that can obstruct airflow.
In everyday use, cabling in and of itself isn’t toxic, but given extraordinary circumstances
it can be. Old cabling jackets might not meet current RoHS requirements. Older cabling also
carries a significant fuel load, which can pose fire threats and can release toxins—such as
halogens—if it catches fire.
Safety issues are important, but if you’re removing old cabling, you also have to consider
the disposal and recycling of cabling. Like with other IT equipment, you can’t just chuck
the cabling into the dumpster; it must be disposed of properly.
When you design your datacenter, you can save future problems and reduce the amount of
abandoned channels through proper management. Infrastructure management systems (such
as MapIT) can provide a detailed monitoring of any moves or changes in your datacenter. This
gives you an up-to-date diagram of the physical layer connections so that channels can be
managed and fully utilized before they become a problem. More information on MapIT and
infrastructure management systems can be found at Link 11-3.

Bigger Bandwidth
When designing or redesigning a datacenter, there’s a balance to be struck between what
you need and what you can spend. If cost were no issue, you’d get the biggest, fastest
equipment you could afford. However, there is a financial reality you need to keep in mind.
That said, it is in your best interest to get the highest capacity equipment you can afford.
Currently, CAT 7/Class F cabling is the highest performing cabling on the market. CAT 7A/
Class FA is due soon, offering 1GHz per channel. This provides a high amount of bandwidth PART V
above the latest 10Gbps speeds for copper. The new cabling is backward compatible with older
technology.
But what if you don’t need CAT 7 cabling right now? Well, you will. And when you do,
you’ll have to take out the CAT 5 or CAT 6 cabling you’ve got and rewire with CAT 7. If
you install the highest performing cable now, you will pay more upfront. However, it will
cost significantly more if you have to keep upgrading every time your equipment gets
a performance boost.
For instance, the installation of a CAT 5e system would need replacing in a few years as
10GBASE-T is implemented to the desktop. Once your organization outgrows CAT 6, you’ll
have to replace it with CAT 7, and so forth.