Date posted: 29 September 2020 – Category: Fibre Optics
Fibre optic cables are made of a type of glass. Each “fibre” is about as thin as a strand of hair. While at first glance it seems fragile, the material is actually quite durable and can outlast copper with proper care.
Fibres are protected by tough cladding and an exterior jacket. However, the very property that allows these glass cables to transmit massive volumes of data at superfast speeds also makes them prone to a host of issues.
Our reliance on fibre can only grow in the future, with the development of ever-faster broadband networks and society’s endless appetite for data. These cables are also increasingly invaluable for business. Bad broadband connections directly siphon productivity from employees. It’s important to know how to spot and troubleshoot the most common issues that plague fibre optic cables.
Fibre optic cables can be installed nearly anywhere–between poles, underground, and through ducts within buildings. That means they’re fairly flexible. However, there is still a limit to how far they can be bent without kinking the cables. Kinked–or damaged–cables due violating the minimum bend radius is a common culprit for patchy data transmission and signal attenuation.
The farthest a cable can bend varies across manufacturers and service providers. Generally, you should not bend a cable any less than ten times its diameter. Tension or pressure also factors into the equation. Cables that are being pulled are under greater tensile stress, which further reduces the amount they can be bent.
Fibre optic cable installation is an exact science. These glass wires are highly sensitive to pressure. Using overly lengthy cables can cause the fibres to wind around each other. Going the opposite direction and overstretching can significantly shorten the lifespan of your cables. One good rule of thumb is to never pull at the jacket, the outer covering that protects the fibres within. Cable installers typically use a pulling grip to keep the pressure off the cable and to keep it from twisting as it’s pulled.
The damage over time from improperly tensed cables can build up and result in breaks and tears. To avoid running into bigger, disruptive problems down the line, it’s best to measure all the distance between the devices and structures the cable will run through, so you can get the appropriate length during installation.
Bar damage from improper installation and mishandling, fibre optic cables can last quite a long time–up to more than 40 years in some cases. But inherent flaws in the silica glass, everyday wear and tear, and the occasional nippy vermin can cause damage at any time.
Use a fiber optic tracer to check for damage. Ordinary laser pointers can work, too. Shine the light through one end of your cable. If it doesn’t reach the other end, then that’s a sign that your cable’s broken somewhere along the way. Torn fibre optic cables can be repaired, but fixing them typically requires hiring technicians to remove the broken lengths and splice the cable back together. Amateur fixes can cause interconnection problems, which leads to signal loss.
Insulated inside thick jackets, the majority of the length of your fibre optic cables are protected against dust and dirt. However, the small fraction of them that connect to patch panels remain highly vulnerable to debris. Fibre relies on glass’s reflective properties to transmit data. Any impurities, no matter how small, can affect performance. As many as 85 percent of outages can be traced back to dirty ends.
Clean your end faces regularly to keep your network at peak performance. Use a scope to check for dirt. You can start by wiping the connector end of the cable on dry cloth. You can also “wet clean” with isopropyl alcohol for more aggressive substances like oil residue from fingers. If you notice that dust is a recurring problem, then you may need to re-evaluate your room’s HVAC systems.
Aside from the span of the cable itself, the connector is where you’ll commonly find performance-breaking issues. Sometimes, the solution can be as easy as securing connectors that have been knocked loose. Or you may need to purchase new connectors that fit better with the cables that you’re using.
Getting the right size is critical. The ferrule–which is the component that aligns the core of the cable with the connector–comes in a variety of diameters. Even a millimetre of mismatch can result in significant connection loss. Some cheap connectors are also built with off-center ferrules.
Fibre optic cables are important, yet sufficient care can fall to the wayside amidst the bustle of a busy office. Cables left unplugged may be stepped on or rolled over by wheeled chairs. You’ll also want to look into your cable management practices. Many use zip ties to sort cables, but these can crimp too tightly, damaging the fibres underneath. Make sure cables don’t snag or get bent by closing and opening doors. If coursing cables through an open space is unavoidable, you can use fibre optic cord covers to protect them.
Rodents have long been the scourge of power lines and telephone cables in cities. Fibre optic cables are equally tempting chew toys. And it’s not only your outdoor cables you have to protect against squirrels. Rats living within the walls of a building can also pose a considerable threat.
Fortunately, there are a number of ways to make your cables less appealing to critters. You can use heavy duty rodent-resistant cables, or cables with thick jackets so mice won’t be able to wrap their mouths around it. If space is a constraint, consider adding repellents that can irritate the sensitive senses of rats or make the cables extremely foul tasting.
There are many elements that can damage fibre optic cables, from improper installation to creatures with an insatiable instinct to chew. Breaks and tears can be hard to spot. Performance drops may be attributed to network service providers, when it’s really your cables that are failing.
Suspect your fibre optic cables may be broken? At TVNet, our team of technicians specialise in fibre optic cable installation and repair. Contact us today to run diagnostics on your cabling infrastructure.
21 Station Road Workshops, Station Rd, Bristol, BS15 4PJ
Steve Morris, Network Manager, Oldfield School