Table of ContentsContentsDesignCosting out a cabling systemMany important decisions can lead a building owner or tenant to justify the installation of a new, universal (standard) cabling system, and it is usually a direct outgrowth of a decision to upgrade a company`s technological capabilities. The first step is to develop a cost estimate for the installation, which involves translating the owner`s needs into a design that fits with the budgeted cost.
InstallationBuilding a flexible fiber network at UC BerkeleyThe Berkeley team created a network flexible enough to support the demands of teaching, production and research.
Product UpdateFiber-optic patch cords must provide high-quality interconnectionStandard fiber-optic patch cords, or jumpers, are short interconnection optical cables with the same connector on each end. [For information on hybrid adapters, with dissimilar connectors, see April 1995, page 10.] According to the Building Industry Consulting Service International Inc. TDM Manual, "the (fiber-optic) cable plant should be interconnected to the optical equipment through the use of optical patch cords (jumpers). This method minimizes accidental damage to the backbone."
StandardsUpdate on networking standardsDuring the past several years, there have been significant developments in computing and communications technologies. Although cabling installers primarily deal with the physical layer of such technologies, they should also know a little about the higher layers, so they can talk intelligently to the network managers who are their customers.
TechnologyComposite cable has its pros and consMore and more installers today are looking into adding to their traditional menu of unshielded twisted-pair, shielded twisted-pair, fiber and coaxial cable. Two of the new options they are looking at are composite cable, a mix of multimode and singlemode fiber, and hybrid cable, a copper and fiber combination.
Hybrid Cables--What You Need to KnowHybrid cabling is a prevalent topic in today`s networking circles. The appeal of these high-performance cables, which typically combine both metallic conductors and optical fibers within the same jacket, is their long-term cost savings and their ability to meet the projected network performance requirements of the future. Due to their construction, however, hybrid cables must meet stringent standards for near-end crosstalk to ensure proper performance.
Crosstalk & FeedbackAsk DonnaFalse CeilingsQ: I work at a chemical plant that manufactures plastics, among other chemicals. My network received two lightning hits this summer. Each time we lost many devices attached to our networks. The networks are of different types and sizes--asynchronous; personal computers to front-end Hewlett-Packard processor; asynchronous to front-end processor via modems; multiplexers; and hardwired to and through buildings of different sizes--some single-story and some two-story.
Installer CertificationQ: I was a private branch exchange technician in the U.S. Air Force. What type of certifications do I need in the civilian world to perform maintenance for commercial telephone companies?
Door SillsQ: Why is it that door sills for telecommunications closets are not allowed by the Building Industry Consulting Service International Inc.`s manual or EIA/TIA-569? Also, if you are supposed to maintain a separation from power lines (1 foot, according to BICSI), are multichannel raceways Category 5-compliant? If you use one section of the raceway for power and the other for telecommunications, then you are not following BICSI or TIA recommendations for Category 5 wiring.
EditorialThe need for informationYou would think that an industry as large and varied, as technologically advanced and as rapidly changing as the cabling industry would be well served when it comes to information. In fact, there is a great deal of information out there, but is it the kind of information that is accessible to cabling installers? Frequently not, I would contend.
A misapplication of technologyInstallers should be aware that they may be liable for damage to equipment connected to surge protection devices if the manufacturer can show that installation errors occurred. During the past two or three years, several manufacturers of surge protection devices have been offering equipment protection programs for equipment connected to their devices. Some of these guarantees are now up to $5 million.
To The EditorGrounding and bondingJust wanted to add a few comments to Mark Waller`s article "Grounding and bonding ensure a safe installation" (see September 1995, page 21).
Products & ServicesIndustry SpotlightFiber Optic Association launchedWith the goal of promoting professional development for individuals working in the fiber-optic industry, The Fiber Optic Association Inc. (FOA) has opened its doors to members.
Will plastic fiber by used in LANs?Suddenly a new competitor may be emerging to challenge Category 5 unshielded twisted-pair cabling for local area networks. Graded-index plastic optical fiber is being touted as having performance and cost advantages over UTP.
OSHA report lists most common violationsHazard communications appears three times in the top 10 of the most commonly cited Occupational Safety and Health Administration violations for the construction industry, according to a 1994 report by the U.S. Department of Labor. The hazard communications standard is based on the employees` need and right to know the hazards and identities of the chemicals they are exposed to when they are working. Employees also need to know what protective measures are available to prevent adverse effects.
Moves, adds and changesAntec Corp. (Rolling Meadows, IL) and Northern Telecom (Montreal, Quebec) announced the signing of a letter of intent for three interrelated business relationships. These relationships are subject to negotiation and execution of definitive agreements and regulatory approvals. The plans involve the formation of a joint venture company to provide integration services for hybrid fiber/coaxial-cable networks to include voice, data and interactive video applications; a joint venture company that wil
New ProductsComponent connector guideA 24-page selector and reference guide includes a photograph and brief description of more than 260 custom and standard connector components. The guide includes descriptions of the 4296-25 mixed coaxial right angle D-Subminiature connectors as well as backshells and grommets and surface mount products.
Surge suppressorsA parallel system of computer-matched metal-oxide varistor arrays in the Interceptor line of surge suppressor systems and filters respond to and intercept spikes and surges. Backed by a five-year warranty, the products have a 300kAIC rating and offer up to 400kAmps surge current capability per phase.
Multimode connector adhesivesAdhesives for multimode connectors range in viscosity, color and cure temperatures. They include room temperature cure systems, colored blue for easy polishing, and heat cure systems, formulated with a three-stage color change to ensure proper mix.
Fiber-optic cable catalogA 128-page catalog with color-coded sections describes each type of this company`s cable, down to the specifications, with cross-sectional drawings, termination diagrams, four-color photographs and specific part numbers. A section explains the benefits of tight-buffered fiber-optic cables.
Prewired blocksSeries M4-5 prewired blocks connect advanced networking equipment to horizontal cabling. The blocks offer Category 5 connectivity in 12- and 24-port versions, and are available with T568A or T568B wiring.
In-stock fiber assembliesIn-stock standard-length fiber-optic cable assemblies include factory terminations at customer-specified lengths as well as pre-assembled cables. The latter includes stock assemblies or customized applications with factory-installed connectors, fiber cut to length and spooled, and assemblies with pulling eyes.
Fiber-optic catalogA 24-page catalog describes a line of fiber-optic test equipment. It includes optical time-domain reflectometers, power meters, light-emitting diode and laser light sources, test kits, visual fault locators, talk sets and laboratory units.
IBM cabling system upgradeThis upgrade, Smart ICS, replaces IBM distribution panels and patch cords with RJ-45-based patch panels and the Patchview cabling management system. The Type-1 cables and wall outlets are retained, thus keeping the major portion of the original investment.
Standards update quarterlyA quarterly publication provides subscribers with current information on changes and additions to premises cabling standards from the Electronic Industries Association and Telecommunications Industry Association, and TIA`s Fiber Optic Division LAN Section. The publication also covers standards currently being developed and discusses BICSI`s involvement.
Category 5 patch cordsData-patch patch cords are made of screened twisted-pair cable terminated with 8-position shielded modular plugs. The cords, offered in seven lengths from 2 to 20 feet, meet all requirements proposed by the Telecommunications Industry Association and Electronic Industries Association for SCTP Category 5 patch cords.
Patch panel kitA "do-it-yourself" kit for fabricating a custom patch panel includes a basic 3.5x19-inch rack panel with six prepunched rectangular openings that accept mating subpanels. A choice of six plastic or anodized aluminum subpanels, each equipped with mounting hardware, completes the assembly.
Cable management systemComponents in this cable management system includes relay racks, wall-mount cabinets, wall-mount relay racks, relay rack accessories, crossconnect accessories and Category 5 patch panels and cords. The system provides a way to mount 19-inch panels and equipment and is designed to maintain necessary bend radius, proper Category 5 cable routing, strain relief and labeling identification.
Cable Installer TipsPlacing cable in a conduit containing trapped waterRunning a pull-string through a conduit containing trapped water can be challenging. If you know in advance that water is present, you can blow both the pull-string and the water through the conduit. Another alternative is to run a long fish tape through the conduit--or run fish tapes from each end, hoping you can hook them up in the middle. However, if you do not have the proper equipment to implement these solutions, you may have to resort to items from the local hardware store.
Firestopping fiber-optic cable penetrationsFiber-optic cables are typically encased in polyvinyl chloride or polyethylene innerducts that protect the cables from damage during installation. When you install fiber-optic cable enclosed by PVC innerduct through walls or floors, you must ensure that the penetrations, or holes, meet the American Society of Test and Measurement E814 standards of two-hour "F" and "T" ratings.
Installing faceplates in the ceilingNetwork systems for computer/engineering laboratories require a significant amount of high-performance networking equipment that is usually installed in a large open area on 6- to 7-foot-high racks or shelves. Cabling workstations in this type of environment can be difficult because of the size of the room and the high concentration of networking equipment set up and moved around on benchtops. The challenge for installers, therefore, is to ensure the cabling performance that the end user require
Wiring a Category 5 110 modular patch panelWhen terminating four-pair cables to the back of a 110-style modular patch panel, it is important to minimize the removal of the outer cable jacket. This is because the individual cable pairs tend to loosen up when they are no longer restrained by the jacket. This loosening may adversely affect the near-end crosstalk loss performance of the Category 5 cable at the point of termination. Although maintaining the jacketed portion of the cable as close to the point of termination as possible minimiz
Testing copper cable for noiseThe copper cable link was tested and certified upon installation, but now that construction is completed and the building is occupied, the data-processing equipment connected to the cable consistently has problems. Retesting the link indicates that the problem is not with the cable or connectors: The problem may be that electrical noise is present in the link.
Maintaining and using a ladder safelyAccording to an April 1995 Bureau of Labor statistics release, 20% of all reported falls were from ladders and 55% of ladder injuries were in the construction trades.
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This IssueNo Image Available Volume 3
Issue 11
November 1995
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| Network Protocols | IP Convergence |
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