In a previous blog post, 5 reasons to buy refurbished Cisco equipment, I talked about five facts to keep in mind as you consider how to proceed with your Cisco hardware solutions.
Well, my engineering group reminded me of something else to consider for any hardware solution, not just a Cisco solution.
It seems that cabling can be an afterthought. Sure, you just used a blended solution of new and pre-owned hardware, where each makes the most sense in your infrastructure and creates a unique and potentially game-changing opportunity to maximize value in your investments.
Cabling is as important as the hardware
But too often IT pros will fall into the familiar pattern of not considering the cabling that connects all this together.
Historically, network designers considered active hardware such as switches, servers, and storage devices to be the most critical network components. Consequently, the fiber-optic cabling (physical layer) design portion of the network was an afterthought. No one wants to Respect Layer One. This mistake led to the purchase of quick, readily available fiber-optic cables of poor quality that have non-licensed connectors, glass from unknown sources, and unknown performance levels. Similarly, the assertion that all fiber-optic cabling is equal is antiquated and false.
Through education, these old ways of network design are fading fast, ushering in a new era of global network design excellence for which world-class cabling is required.
The notion of treating fiber-optic cabling as an afterthought needs to change due to multiple factors. These include next-generation transmission speeds with far lower allowable losses, network virtualization initiatives, and the most consequential, the technical advances of the light transmitters inside the active devices.
In the 1980s and early 1990s, the only network light transmitter available was the light emitting diode (LED). With the transition to Vertical Cavity Surface Emitting Lasers (VCSELs), the light within the fiber-optic core area became more focused, lighting up a much smaller area of the core and enabling higher speeds, greater bandwidth, and overall faster Ethernet and fiber channel protocols.
These newer light transmitters (VCSELs) demand far superior fiber-optic cabling. The light launch nature of the VCSEL makes the end face geometry and the polish far more significant than in the past. As a result, most network designers today view the physical-layer fiber-optic cabling to be of equal, or even greater, importance as the active components of their network.
Active network hardware gear will be obsolete or replaced in three to five years from date of purchase, according to current trends. Fiber-optic cabling of good quality usually comes with a lifetime warranty. Fiber cabling purchased today can easily last far into the future if good design practices are followed and emphasis is placed on the quality of the cabling.
Fiber-optic cable manufacturing includes industry standards for connector loss, thermal aging, humidity, thermal shock, thermal cycling, vibration and other test criteria. Given the long life potential of a cable assembly, and the potentially harsh environment in which they will be utilized, it is good design practice to purchase assemblies that exceed the industry standards.
What are the industry standards for cabling?
Below is a list of industry standards for network cables:
- Thermal aging: 85°C for 168 hours
- Humidity: 75°C at 95% relative humidity for 168 hours
- Thermal shock: -40°C to 75°C
- Thermal cycling: -40°C to 75°C for 21 cycles
- Vibration: 1.5mm P-P 10Hz to 55Hz
- Flexure test: 100 cycles at 2 lbs
- Twist: 10 cycles at 3 lbs
- Off axial pull (transmission): 3.3 lbs at 90° pull direction
- Axial pull (transmission): 4.5 lbs
- Axial pull latch: 15 lbs
- Optical fiber macrobend performance per ITU-T G.657 and ITU-T G652.D recommendations
Logically, the best practice would be to select a cabling manufacturer that has invested in equipment to test for the environmental industry standards listed above. Having this equipment on site would enable the manufacturer to periodically re-verify that the materials supplied to them by their OEM vendors continue to meet the standards they expect and promise to data center managers.
So, the next time you purchase hardware, pre-owned or new, remember to give the same consideration to the cables you purchase.
After all, you wouldn’t order a burger without ordering fries, and you shouldn’t buy sub-standard cabling to serve large-scale networking equipment. It’s imperative for companies to protect the investments they make in the technology purchases.