Debunking Common Misconceptions with Fiber Optic Cable

Written by Don Schultz, trueCABLE Senior Technical Advisor, Fluke Networks Copper/Fiber CCTT, BICSI INSTC, INSTF Certified

One of the biggest technological advances in recent years with wired networking is fiber optical cable. Capable of extremely high speeds and great distances this type of communications cable has managed to supplant (or even replace) copper twisted pair Category cable “aka Ethernet” in many installations.

Fiber optic is the newest and least familiar type of communications cable to DIY individuals and even experienced structured cabling system installers. Your average person will typically pass over this cable type due to lack of familiarity and what does lack of familiarity breed? Fear. Some of that fear was and is still well founded, although things are changing that make fiber optic much more accessible and in some cases even easier to install than the traditional copper cable technologies. Fiber optic has some use cases that not only make it the ideal choice, but really the ONLY choice for certain installation projects -- while being plug and play!

What does not change, though, is information posted on the Internet. As we all know, “once on the Internet always on the Internet”. So when the average person goes to research fiber optic cable they are met with horror stories about easy breakage, personal injury, and extremely difficult terminations. No one person is controlling the narrative, so this information gets mixed in with more current information and things can get quite confusing. A lot of misconceptions remain and myths have formed. Let’s peel some of this back!

As is typical, trueCABLE has created a video companion (not replacement) for this blog that helps to further clarify our current topic. Please take a look…but be sure to come back here and continue reading as the written blog adds even more information.

What You’ll Learn in This Blog

• How fiber optic differs from traditional metallic communications cable
• Advantages of fiber optic cable
• Disadvantages of fiber optic cable
• Clarifying what makes fiber optic more challenging for new installers

While discussing these topics, we will address common misconceptions surrounding fiber optic cable.

How is Fiber Optic Cable Different?

Physical differences

Fiber optic cable uses a completely different way of transmitting data from traditional methods. Here are the most significant differences:

• Fiber optic cable uses light pulses (in the infrared wavelength) instead of electrical impulses to transmit/receive
• The data is transmitted through a glass conductor as opposed to a copper conductor
• Fiber optic conductors do not carry any electrical voltage
• Fiber optic conductors are extremely thin as compared to what is required for traditional metallic conductors
• The type of connectors used is completely different from copper Ethernet

For more on how fiber optic cable is constructed, please see Basic Components of a Fiber Optic Cable.

Transmission equipment differences

• Fiber optic cables will require translation from electrical to optical via a device known as a transceiver. Transceivers can be built-in to an Ethernet switch or as an accessory device via SFP/SFP+ (small form-factor pluggable) modules. The receiving end will likewise require conversion from optical back to electrical impulses as computers do not natively make use of light impulses.

• Copper Ethernet cables are simply plugged into an Ethernet switch via a RJ45 port, requiring no translation to optical light pulses. The reverse is also true for the receiving equipment, as a direct connection can be made without any conversion.. If you are curious about Ethernet RJ45 ports, please see What is an Ethernet Port? The Complete Guide to Ethernet Ports.

EMI/RFI/Environmental differences

• Fiber optic cable is absolutely immune to any form of EMI/RFI (electromagnetic / radio frequency interference) such as powerful motors, antennas, and electrical circuits. You must keep your distance or use shielding with metallic communications cables. To see just how drastic that effect can be on copper Ethernet cable, see Top 2 Things to Consider When Running Ethernet and Power Cable.
• Traditional metallic communications cable like Ethernet is also affected by ambient temperatures (copper resistance increases with heat rise). To see how copper twisted pair Ethernet is affected by temperatures, please look at Temperature's Effect on Ethernet Cable Length.

Advantages of Fiber Optic Cabling

Installation environment advantages

Fiber optic can go places that traditional Ethernet cannot. Fiber optic cable is able to operate with impunity in adverse environments without adding shielding or shortening lengths to compensate for Insertion Loss.

Insertion Loss (IL) is a measurement of signal degradation that naturally occurs due to length or other factors.

Data transmission distance advantages

Fiber optic cabling can transmit data much farther than traditional metallic communications cables without any boosting or renewing of the signal, greatly easing installation effort. This means fiber optic is ideal for getting signal to places that otherwise would need to revert to inferior wireless technologies or even get no signal at all.

Ease of installation advantages

• Fiber optic cables are significantly lighter and thinner than Ethernet cable, dramatically increasing communication circuit counts and simultaneously reducing the amount and weight of cabling required as compared to metallic cables. Consider that a 12 fiber distribution cable is only as thick as a SINGLE Cat6A Ethernet cable, and now splice a ready to go “pig tail” onto that distribution cable. That is 12 communications circuits as opposed to one, and in the same diameter, with less weight, and at far faster potential speeds. Give that some thought!
  

• Fiber optic cable is more durable when pulling cabling into place. Consider that fiber optic cable is capable of withstanding 50 ft-lbs of pulling force as opposed to 25 ft-lbs of pulling force for copper twisted pair Ethernet. In addition, most fiber optic conductors are now “bend insensitive” and “tight buffered”. This means the fiber can be pulled relatively hard and bent relatively sharply before an issue occurs. In the past, fiber optic cables had to be handled with kid gloves. Merely violating a strict bend radius or the fiber cable hitting a hard surface with sufficient force would be enough to shatter the fibers. This is no longer true except for a type of fiber known as “loose tube”.

To read more about bend insensitive fiber, please see Bend-Insensitive Fiber – What Is It?

Performance advantages

Fiber optic cable is able to transmit data at much higher speeds than Ethernet cable. Ethernet cable is restricted to 40Gbps at 100 feet. Fiber optic can easily reach 100 Gbps for hundreds of feet. To see a detailed breakdown of fiber vs copper Ethernet speeds, please see Cat7 vs Cat8 vs Fiber Optic Cable: Ultimate Guide [2024].

Disadvantages of Fiber Optic Cabling

Keep in mind that all of these disadvantages are as of the time of writing. The traditional disadvantages surrounding fiber optic cable are slowly being worked through and becoming nullified over time.

Training and skill level

As with any new technology or skill, there is going to be a learning curve. Consider that at one time you did not know how to pull and terminate copper twisted pair Ethernet cable. How long did it take you to get fully up to speed? It probably took a while and you had to learn new terms, buy unfamiliar equipment, and practice new techniques. The same is true for fiber optic installation as well, but there is an added barrier…formal classroom or on the job training is ideal for fiber optic cabling and that training can become expensive.

Safety concerns are involved when dealing with bulk fiber optical cable that is not already connectorized and ready to go. Bare fiber shards are glass. Very thin glass can easily snap and shatter and poses hazards involving serious personal injury or even death unless appropriate precautions are taken.

Another factor is that while fiber optic conductors are quite durable prior to stripping off the various protective coatings, it is all too easy to damage or destroy the bare glass during said stripping process. Ask anyone who has stripped fiber optical cable how many tries it took before they became proficient!

Thus, proper training remains a barrier to DIY individuals or weekend warriors. That said, this blog and video might help: Preparing your Fiber Optic Cable for Connectors or Splices.

Tool & Accessory Costs

Copper twisted pair Ethernet cable is practically a commodity item, as are the associated Ethernet tools and Ethernet termination hardware. The terminations and tools are relatively inexpensive. There is a plethora of information about how to use and install the products to the point that DIY/casual installers can get up to speed relatively quickly with minimal expense.

Not so with fiber optical cable. Although bulk fiber and fiber optic patch cords are quickly becoming commodity items, the moment tools are involved the level of precision and cost increase considerably. In some cases, as with fusion splicers, costs for a fusion splicer worthy of the task start at $5,000 and go up from there. Specialized training is also required for these devices, and not all of that training is free or readily available. Fortunately, the cost of mechanical splicing technology is coming down but mechanical splicing is less precise as well. Please see Mechanical Splicing vs. Fusion Splicing: Which Is Right for Your Fiber Optic Needs? to see which one might better suit your needs.

PoE (Power over Ethernet) Capability

Probably the biggest downsize to fiber optic cable is the inability to transmit data and electricity over the same conductor to power up PoE devices. This is a huge advantage for copper twisted pair Ethernet and coaxial cable. Metallic communications cables are great for carrying electrical voltages (low voltage of course). This downside restricts fiber optical communication to key areas of your installation as opposed to a direct replacement for all of your communications cable types.

Frequently Asked Questions

Will fiber optic cable replace copper Ethernet and coaxial cable types completely?
No. Well, not anytime soon. There is a huge amount of copper cabling installed currently, and these systems are in daily operation. New installations are making use of fiber optic technology more than ever (FTTD or Fiber to the Desktop) for example, but copper twisted pair Ethernet is still involved somewhere. Current and near future installations will be hybrid in nature where WiFi, copper Ethernet, and fiber all play a role and are used in their best use cases where it makes sense. Coaxial cable, on the other hand, is a much older technology that is being replaced due to escalating bandwidth needs for Internet and service goals to rural areas. Coaxial cannot go the distance for this, but fiber optic can! It should be noted that coaxial cable for actual Ethernet data transmission in a local area network is already dead, being buried quite effectively by copper twisted pair Ethernet many years ago.

Will fiber optic ever be viable for home installations?
Yes! In fact, with FTTH (Fiber to the Home) Internet Service Providers are already bringing fiber right to your home. The question is whether fiber will be used inside the home itself, right? “Prosumers” are already utilizing fiber in the home in a limited way. Typically this is seen as high speed Ethernet switch to Ethernet switch interconnections using pre-connectorized patch cords. Over time, fiber optic will supplant and eventually replace copper Ethernet. This will take time, likely measured in decades.

Wrapping Up: Debunking Common Misconceptions with Fiber Optic Cable

At this point you understand that fiber optic cabling, installation, and accessibility as a technology has come a long way since the early days when it was an extreme specialty cable that only certain people got to look at, and even fewer got to work with. trueCABLE is dedicated to not only educating around the topic, but to developing products that will bring fiber optic installation right into the purview of at least the “weekend warrior” type of installer. Who knows what the future will hold? Well, you can be sure fiber optic will be a large part of it!

So, there you have it. Another burning question answered by the folks at trueCABLE. As always, HAPPY NETWORKING!

Ready to Learn More?

trueCABLE’s Cable Academy has a wealth of information providing educational materials covering general topics like this one but also takes many deep dives into copper Ethernet, coaxial, fiber optic cable, and more! Take a look as you will be glad you did!

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