FAQs

Frequently Asked Questions (FAQs)

  1. My department needs to deal with a lot of moves, adds and changes (MACs). How can I accomplish these cost-effectively and still use fiber?
  2. Does it cost more to install fiber cable than UTP cable?
  3. How can I effectively incorporate VOIP into an all- fiber network?
  4. Is a patch panel required in the TR?
  5. In your Network Architecture Model, environmental controls are a significant expense. Are they really necessary?
  6. Is fiber more difficult to install than copper?
  7. Is it easy to test fiber links?
  8. Are there any applications that require fiber?
  9. I have an existing copper infrastructure, what's the most cost-effective way to upgrade to fiber?
  10. What's the difference between 62.5 micron and 50 micron fibers?
  11. Why do I need to install optical fiber?
  12. I already have TRs in my building, is Centralized Cabling appropriate for an upgrade?
  13. Aren't fiber solutions more expensive than UTP copper solutions?
  14. Do media converters add a point of failure to the network? Why would I want to use them?
  15. What are SFF connectors, and why should I consider them?
  16. Since fiber is made of glass, will it survive harsh conditions?
  17. In TIA standards what is the difference between a TSB and an Addendum?
  18. Can the same fiber optic transceivers that are used with OM3 fiber, like X2-10GB-SRs, be used with OM4 fiber or are there new transceiver types that need to be used?
  19. Are Bend Insensitive Multimode Fiber approved by standards?

  1. My department needs to deal with a lot of moves, adds and changes (MACs). How can I accomplish these cost-effectively and still use fiber?^top
  2. You should consider using Fiber to the Telecommunications Enclosure (FTTE). In this architecture, electronics are typically centralized in a singe Telecommunications Room, and then the fiber is run to a Telecommunications Enclosure (TE). The final distribution from the TE can be by wireless, copper or fiber. This architecture can help you leverage the benefits afforded by fiber by moving closer to the user, while at the same time providing extreme flexibility.

  3. Does it cost more to install fiber cable than UTP cable?^top
  4. It shouldn't. But we have heard that in some parts of the country, installers are asking for premiums of up to 30% more to install fiber cable! If you receive quotes that show fiber installation to be significantly more than UTP copper, we encourage you to refer to our Network Architecture Model, which shows that fiber cable installation can cost the same, or even less than copper. Now that fiber has been installed in the backbone for more than a decade, most installers have the training and comfort level with fiber cable to make installation cost efficient.

  5. How can I effectively incorporate VOIP into an all- fiber network?^top
  6. There are several solutions for this application. The main issue is how you power your talk sets. There are a number of manufacturers that sell talk sets or IP phones. These phones come in different styles with a variety of features. Some are traditional desktop phones, which you plug into an AC outlet and connect via an RJ style patch cord to the network. If fiber is run to the work area, you add a media converter in the work area to change from fiber back to copper for the phone. Another option is to purchase a headset that attaches to the desktop via a USB port or serial port. Typically, with the purchase of the headsets all the necessary software to use the headset to access the VOIP service is included. The headsets utilizing USB ports bypass the desktop's soundcard and give good quality sound. For the headsets that utilize serial ports, you may need an additional module. There may be IP desktop phones that are available with a fiber interface that is powered by an AC adapter and plugged into conventional wall outlet. Another approach is to deploy fiber to the TE and then use a copper cable from the zone to the desk for the talk set.

  7. Is a patch panel required in the TR?^top
  8. Not necessarily. Eliminating the fiber patch panel is consistent with TIA/EIA 568 B. When using this configuration, all rerouting is done at the Central Distribution Panel (CDF). Keep in mind that according to the TIA/EIA 568-B.1 Annex A if the run is less than or equal to 90m a pullthrough is acceptable without an interconnect or splice point. However, if the distance is greater than 90m, to be standards compliant, you must put in either an interconnect or splice point.

  9. In your Network Architecture Model, environmental controls are a significant expense. Are they really necessary?^top
  10. It depends on the nature of the building. If the temperature in the TR gets too hot or too cold it can cause premature failure of the electronics. For example, when a building needs heat, often times the TR needs cooling. Environmental control is particularly important during weekends and vacation time, even though temperatures in the main building may not need to be so highly regulated.

  11. Is fiber more difficult to install than copper?^top
  12. It depends on the comfort level and training of the technicians. Since fiber has been accepted as the standard choice for communications backbones for many years, today's installers are generally comfortable with the technology but there is a learning curve for those just starting out. Of course, the same could be said of new generations of copper cabling. The new generation high-speed copper cables require more stringent and time-consuming installation techniques than were required in the past. Compared to newer grades of copper cable, fewer regulations exist on the methods by which optical cable is pulled and terminated. In addition, there is no need to worry about the location of EMI/RFI sources during installation. Also, with fiber cables, there are no requirements for mitigating techniques when migrating to 10GbE and higher data rates as there are with UTP copper media.

     

  13. Is it easy to test fiber links?^top
  14. Fiber links are relatively straightforward to test. Since fiber cable facilities are not affected by near-end cross talk (NEXT) and their operating performance is not affected by frequency, technicians can test runs by simply measuring the attenuation of the optical fiber link. In comparison, to verify the performance of Category 5e links, tests must be conducted for attenuation, cable length and crosstalk. Technicians must also perform attenuation and NEXT tests across the entire frequency range of 1-100 Megahertz or higher because the performance of copper-based systems changes at different frequencies.

  15. Are there any applications that require fiber?^top
  16. Most applications are media agnostic – that is, they are supported by a variety of different cable types including copper and either multimode or single-mode fiber. While copper can be used for many high-speed protocols, the link distances supported by standards are often very short. For example, the latest 40/100Gbps Ethernet standards only incorporate a 7 meter link distance for copper Twiinax cable, and UTP is not a supported media. Multimode fiber, on the other hand, can support 40/100Gbps links up to 150 meters, while single-mode fiber can support 10 km link lengths. The increasing need for security is also driving users to deploy fiber. In fact, it is required for many government applications.

     

  17. I have an existing copper infrastructure, what's the most cost-effective way to upgrade to fiber?^top
  18. For companies that want to leverage their legacy electronics, need to upgrade only a portion of their network, or do not have the resources to upgrade their entire network at once, fiber can be installed incrementally. For these users, media conversion technology offers them a controlled migration strategy. Media converters do just what their name implies -- the devices convert the signal from one type of media to another, allowing seamless links between different media and supporting incremental upgrades to fiber. Media converters also allow users to continue to use their existing electronics, leveraging their existing investment.

  19. What's the difference between 62.5 micron and 50 micron fibers?^top
  20. Physically the two fiber types differ in the diameter of their cores, the light-carrying region of the fiber. This is signified by the numeric nomenclature. In 62.5/125 fiber, for example, the core has a diameter of 62.5 microns and the cladding diameter is 125 microns. In terms of performance, the difference lies in the fibers' bandwidth, or information-carrying capacity. Bandwidth is actually specified as a bandwidth-distance product with units of MHzkm. The bandwidth needed to support an application depends on the data rate. As the data rate goes up [MHz], the distance that rate can be transmitted [km], goes down. Thus, a higher fiber bandwidth enables you to transmit at higher data rates or for longer distances. 50 mm multimode fiber offers nearly three times more bandwidth (500 MHzkm) than FDDI-grade 62.5 mm fiber (160 MHzkm) at 850 nm. Network planners often choose 50 micron fiber when they know the network will need to carry high bandwidth applications over longer link distances, or when they anticipate running higher speed protocols in the future.

  21. Why do I need to install optical fiber?^top
  22. Network managers choose to install optical fiber for several reasons, depending on their application. A few of the major reasons are listed below

  • Longer link lengths: Because of its high bandwidth and low attenuation, fiber cable can support much longer link lengths when compared to the industry standard of 100 meters for unshielded twisted-pair (UTP) copper cabling. For example, with 10GbE copper is limited to 100m, but OM4 multimode fiber can support at least 400m.  The longer lengths that fiber can support allow designers much more flexibility for laying out their infrastructure and maximizing the use of their real estate.
  • Network Infrastructure Longevity: Today’s multimode fibers offer users the ability to support their network needs well into the future. With laser-optimized multimode fibers (OM3 and OM4) companies can easily migrate to 40 or even 100 Gigabit Ethernet and higher in their backbones. These fibers offer enough “headroom” to support anticipated applications for at least 10 to 20 years!
  • EMI/RFI Immunity: In some installations -- particularly industrial applications and some schools and hospitals -- electromagnetic interference (EMI) or radio frequency interference (RFI) from fluorescent lighting or industrial equipment can cause network problems. Because fiber is dielectric, it is immune to these problems. In addition, unlike copper facilities, all-dielectric fiber cabling systems do not conduct lightning strikes or electrical currents that can damage sensitive electronic transmission equipment.

 

  • I already have TRs in my building, is Centralized Cabling appropriate for an upgrade?^top
  • Centralized cabling is more frequently used for new builds, because then network designers can plan spaces more efficiently. However, there are existing installations that have been able to successfully "reclaim" space that had been allocated to TRs. Some additional benefits of going to a centralized fiber architecture is that your port utilization improves and the number of points of administration decreases. By moving all of your equipment into one central location it is also easier to secure and troubleshoot the network. This configuration also enables greater energy efficiency because you eliminate the need for cooling in the TR and for the inclusion of a UPS, or the availability of an uninterruptible power supply distributed from a central source.

  • Aren't fiber solutions more expensive than UTP copper solutions?^top
  • Not necessarily. We encourage you to download our interactive Network Architecture Model where you can compare the installed first costs of different architectures and media. In some applications, all-fiber systems are less expensive to install  than networks using fiber in the backbone and UTP copper in the horizontal. If you look at lifecycle costs as well as installed first costs the rational for installing fiber-based systems often becomes even more compelling.

  • Do media converters add a point of failure to the network? Why would I want to use them?^top
  • Media converters have extremely high reliability statistics. In fact, although some companies have viewed them as a temporary, migration solution, they have been so pleased with their performance that they made them permanent. Media converters are ideal for companies that have an existing copper infrastructure that want to upgrade the parts of their network that need increased bandwidth or higher speed transmission rates now, while at the same time leveraging existing electronics.

  • What are SFF connectors, and why should I consider them?^top
  • Small Form Factor (SFF) connectors were introduced several years ago by a number of different manufacturers. They are smaller than traditional fiber connectors, with a footprint similar in size to copper-based connectors. As a result, they hel increase port density, reduce the cost of hubs and switches, lower patch-panel and enclosure costs, and reduce jumper costs. They are easy to install, making fiber even faster to install.

  • Since fiber is made of glass, will it survive harsh conditions?^top
  • Optical fiber is not your typical kind of glass. Made of ultra-pure silica, it is an extremely strong material that has the ability to handle exposure to temperature and pressure extremes. In fact, tensile strength (resistance to pulling) of optical fiber exceeds 600,000 pounds per square inch -- making it stronger than copper or steel strands of the same diameter and easily surpassing the strength requirements of today's communications applications. When cabled, glass fiber is protected and further strengthened by aramid or fiberglass yarns, a fiberglass rod, and/or an outer jacket constructed of non-conductive materials.

  • In TIA standards what is the difference between a TSB and an Addendum?^top
  • A TSB is a Telecommunications Services Bulletin. It is purely informational: we might look at a subject, collect information and share it with the industry. There is no normative information, - no "shall" statements. TSBs are often stepping stones in the standards process as we start to explore topics that might become part of a standard. In fact, a TSB can be referenced by a standard. An addendum is an official addition to a publish standard. Anything in the addendum has the same enforcement as a full, published standard. The contents can be normative or informative depending on the content and how the engineering committee positions the material as an addendum.

  • Can the same fiber optic transceivers that are used with OM3 fiber, like SFP +
    10Gbps pluggable modules, be used with OM4 fiber or are there new transceiver types that need to be used?^top
  • Yes, you can use the same fiber-optic transceivers for both OM3 and OM4 fibers because the two fiber types are basically the same except that OM4 fiber has higher bandwidth. The IEEE 10Gbps Ethernet standard states that 300m OM3 and 400m OM4 link lengths are supported with 10GBASE-S compliant transceivers.

  • Are Bend Insensitive Multimode Fiber approved by standards?^top
  • The TIA/IEC standards bodies are currently in the process of evaluating how the existing multimode fiber standards can be updated to include the new Bend Insensitive Multimode Fibers. Currently, there are multiple designs for Bend Insensitive Multimode Fibers and those designs are being evaluated to determine how they affect the connector loss, bandwidth and system performance measurements and qualification processes. If you are interested learning more about the status of BIMMF or participating in the discussion you can access the schedule for TR-42.12 here and download recent meeting reports.