Color by Numbers

Don't always judge a cable by its color

Although it may be difficult to identify the specific type of copper cable just by looking at the jacket color, it’s a “color by numbers” method when specifying fiber optic cable. Outdoor cables (both copper and fiber) are usually black; however, indoor copper cables can come in an assortment of jacket colors, depending on the end user or installer’s preference. Some choose the common blue or gray, while others choose custom colors – such as brown, which was the case of Hershey Company to match their milk chocolate. And, it’s not unusual to find a combination of colors at one location to identify the different services or applications of twisted pair – such as yellow for voice, blue for data, red for security.   However, unlike the rainbow of jacket color offerings of copper, indoor fiber optic colors are yellow, orange or aqua, if the manufacturer follows the TIA-598-C standard.

The TIA-598-C standard distinguishes among indoor fiber optic cables to corresponding fiber properties. Although it identifies the jacket color to be used on cables containing only one fiber type, there are exceptions for cables that contain several types, and a printed legend on the outside jacket is then required.
If the fiber optic jacket is yellow, the fiber optic cable is immediately recognized as singlemode and the “numbers” are 8-9µm for the core diameter; 1310 and 1550nm for the operating wavelength; bandwidths greater than 10 GHz; and distances for over 2km. Multimode fiber cables have many more constructions and corresponding characteristics to match its numbers to the jacket colors – either orange or aqua. Orange was the common multimode cable color until high-speed VCSEL technology for 10 Gigabit Ethernet was developed. With the emerging generations of laser-optimized 50µm multimode cables, better known by their numbers as OM3 (Optical Multimode) and OM4, came the aqua jacket. All major fiber optic cable manufacturers who follow the standards use this color to delineate these higher grades of 50µm cables. 
Color Blindness not allowed
Per the TIA-598C the aqua jacket designation should only be utilized for OM3 and OM4 multimode fiber cables containing laser-optimized fibers with a MINIMUM effective modal bandwidth* of 2000 MHz*km and corresponding distance guarantees of 300 and 550 meters, respectively, for 10 Gb/s. Anything less than that should be designated with an orange jacket as OM1 or OM2. To follow is the chart that differentiates between the OM1, OM2, OM3 and OM4.
OM chart
*Note: There are two bandwidth measurements – over-filled launch (OFL) and effective modal bandwidth (EMB). They correlate the different light sources. EMB utilizes a laser, or VCSEL, and OFB an LED.
In addition, the TIA-598-C standard has adopted the aqua jacket to incorporate performance requirements of new TIA-492AAAD standard for both OM3 and OM4.   However, even with these industry standards, which by definition only provide recommended practices, as opposed to mandatory codes, there are other manufacturers that use the aqua jacket for cables that do not meet the OM3 and OM4 specifications.   This has created confusion to the end-user if they receive cables that are aqua jacketed, but do not meet the standards’ requirements. 
End users should require manufacturers to provide proof that the performance characteristics of enhanced multimode fiber are carefully measured and controlled. Performance of OM4 fiber is verified using the same criteria as OM3, but to tighter specifications. One method is to make sure that each fiber passes stringent Differential Mode Delay (DMD) specs outlined by TIA-455-220 or IEC 60793-2-10.
Berk-Tek’s Cable Pass with Flying Colors
For five years, way before the standards were ratified, Berk-Tek has been a leader in OM3 and OM4 technology by offering two types of fibers that meet or exceed OM4. GIGAlite™-10FB glass meets OM4 requirements, whereas the GIGAlite-10XB, the industry’s highest performing laser optimized 50µm fiber, surpasses the standards with a bandwidth of 4900 MHz*km at 850nm and a reach surpassing 600 meters.
OM4 will be increasingly important as bandwidths exceed 10 Gb/s. Already under development are applications, such as in the data center environment that could reach speeds to 40 Gb/s in the next five years. With the additional headroom of Berk-Tek’s premium “XB” fiber, Berk-Tek is positioned with cables today to meet these applications of tomorrow and proudly dons the aqua jacket.

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Carol Oliver Berk-Tek Marketing Analyst