Cim 20070701 jul_2007


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Cim 20070701 jul_2007

  1. 1. Contents Zoom In Zoom Out For navigation instructions please click here Search Issue Next Page ____________________ Contents Zoom In Zoom Out For navigation instructions please click here Search Issue Next Page
  2. 2. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F Exceptional optical performance comes naturally. Nothing is more treasured in field termination than exceptional optical performance. The secret to UniCam® Pretium™- Performance Connectors is inside – a laser-cleaved, factory-polished fiber stub that ensures outstanding connectivity in a no-epoxy/no-polish (NENP) connector. UniCam Pretium-Performance Multimode Connectors offer 0.1 dB insertion loss. And UniCam Pretium-Performance Single-Mode Connectors enable 0.2 dB insertion loss. That’s exceptional optical performance in less than a minute per fiber, from the most widely deployed NENP connector on the market. Naturally ... Customer-focused innovation is second nature at Corning. © 2007 Corning Cable Systems LLC / LS-02413 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  3. 3. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F Turn your cable tester into an OTDR and watch the transformation begin. See how the DTX Compact OTDR Module can turn your cable tester into an OTDR and your staff into fiber experts – to completely transform your fiber business. Imagine. A cable tester that becomes a compact, easy-to-use, full-featured OTDR. Better yet, imagine what that means for your business. A single tool to test copper and fiber. An OTDR your current technicians can easily use. Fiber jobs you couldn’t do before. Just snap the DTX Compact OTDR module onto a DTX mainframe – the industry’s benchmark for cable certification. Now you’re ready to test like a fiber expert. Perform Basic (Tier 1) and Extended (Tier 2) fiber certifica- tion. Perform powerful single-ended trouble- shooting. Deliver professional documentation. Win jobs that require OTDR testing and watch your revenue and profits increase. Look to the new DTX Compact OTDR and watch the transformation begin. Go to to enter to win a DTX Compact OTDR and see a live demo. N E T W O R K S U P E R V I S I O N ©2007 Fluke Corporation. All rights reserved. 02152 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  4. 4. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGSF Our U.S. area of expertise. No matter where you’re located, our fiber optic cable products are there. Optical Cable Corporation has built a network of reliable stocking distributors and a dedicated sales team committed to getting you the best fiber optic cables for your requirements when you need them...where you need them. For over 20 years, we have been manufacturing the broadest range of top-performing tight-buffered fiber optic cables for most applications in the government, military, and commercial markets. Your order is our top priority. Contact Optical Cable Corporation for a stocking distributor nearest you. We are where you are. 1-800-622-7711 5290 Concourse Drive • Roanoke, Virginia 24019 • Phone 540-265-0690 • C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGSF
  5. 5. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F COVER IMAGES SUPPLIED BY ANIXTER. JULY 2007 VOL. 15, NO. 7 ABOUT THE COVER Using vendor-neutral testing, Anixter’s features 15 Infrastructure Solutions Lab is demonstrating real- The myths and realities of world IP convergence of shielded, screened cabling security and networking Potential users must separate fact from fiction concerning noise infrastructure products so immunity, grounding, and the antenna effect. VALERIE RYBINSKI that customers can know 25 what will work best for their installation before investing. Abandoned cable removal TO LEARN MORE, SEE PAGE 49. a dogged challenge for all Unfortunately, for everyone, ignoring the issue won’t make it go away. PATRICK McLAUGHLIN 29 Twisted pair options for 10-Gigabit Ethernet Conducting appropriate tests will help ensure your medium of choice is ready for high-frequency, high-speed transmission. HUGO DRAYE 37 Products and technologies meeting myriad challenges Latest innovations aim to alleviate problems associated with cable management, power consumption, security and, oh-by-the-way, signal transmission. PATRICK McLAUGHLIN & STEVE SMITH 40 WLAN goes fat to thin and back again When the industry moved to centralized wireless solutions with switch-based controllers, many thought the war between “fat” and “thin” was over. But now it appears the battle is still on. BETSY ZIOBRON departments 6 Editorial Your network’s health is everything 49 INDUSTRY SPOTLIGHT ■ Anixter lab integrates networking, security 9 Ask Donna ‘Abandoned’ headaches ■ Big Blue digging deep for data center purge begin early ■ Cat 6A solution undergoes 10-GbE traffic test 54 New Products ■ Flexible racks meet military media center specs 56 Product Focus: ■ Wireless Gigabit Ethernet on-the-fly FIBER-OPTIC POLISHING EQUIPMENT CABLING INSTALLATION & MAINTENANCE (ISSN 1073-3108), a trademark, is published 12 times a year, monthly, by PennWell Corporation, 1421 South Sheridan Road, Tulsa, OK 74112; telephone (918) 835-3161; fax (918) 831-9497; Web address Editorial offices: 98 Spit Brook Road, Nashua, NH 03062-5737; telephone (603) 891-0123. © 2007 CABLING INSTALLATION & MAINTENANCE. All rights reserved. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by CABLING INSTALLATION & MAINTENANCE (ISSN 1073-3108), provided that the appropriate fee is paid directly to Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923 USA; (978) 750-8400. Prior to photocopying items for educational classroom use, please contact Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923 USA; (978) 750-8400. For further information, check CCC Online at the following address: All rights reserved. No material may be reprinted. Bulk reprints can be ordered from Diane Troyer, telephone (603) 891-9135. Corporate officers: Frank T. Lauinger, Chairman; Robert F. Biolchini, President and CEO. POSTMASTER: Send address changes to: CABLING INSTALLATION & MAINTENANCE, Circulation Dept., P.O. Box 3280, Northbrook, Il 60065-3280. Return undeliverable Canadian Addresses to: P.O. Box 1632, Windsor, ON N9A 7C9. Periodicals postage paid at Tulsa, OK 74101 and other additional offices. Subscriptions: In the U.S.: one year $74; Canada/Int’l surface : one year $84; International via air: one year $100. If available, back issues can be purchased for $16 in the U.S. and $21 elsewhere. We make portions of our subscriber list available to carefully screened companies that offer products and services that may be important for your work. If you do not want to receive those offers and/or information, please let us know by contacting us at List Services, CABLING INSTALLATION & MAINTENANCE, 98 Spit Brook Road, Nashua, NH 03062-5737-“Canada return address: PO Box 122, Niagara Falls, ON L2E 6S4”. Cabling Installation & Maintenance ■ July 2007 ■ 3 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  6. 6. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F Chief Editor / Patrick McLaughlin (603) 891-9222 • Executive Editor / Steve Smith (603) 891-9139 • Senior Editor / Matt Vincent (603) 891-9262 • Circulation Manager / Michelle Blake (603) 891-9360 • Art Director / Kelli Mylchreest Lead Illustrator / Dan Rodd Senior Vice President/Group Publishing Director Mark Finkelstein (603) 891-9133 • Associate Publisher/National Sales Manager Ed Murphy (603) 891-9260 • CABLING INSTALLATION & MAINTENANCE EXECUTIVE AND EDITORIAL OFFICES PennWell ATD 98 Spit Brook Road Nashua, NH 03062-5737 Tel: (603) 891-0123, fax: (603) 891-9245 Internet: SUBSCRIPTION INQUIRIES: For subscriptions or to change your format to print or digital, please go to: Subscriptions outside the USA are available in digital format only. CORPORATE OFFICERS Chairman / Frank T. Lauinger President and Chief Executive Officer / Robert F. Biolchini Chief Financial Officer / Mark C. Wilmoth ADVANCED TECHNOLOGY DIVISION Senior Executive Assistant Carol Woodward Tel: (603) 891-9112, fax: (603) 891-9287 VP Audience Development / Gloria S. Adams ATD PUBLISHING SERVICES DEPARTMENTS Art Director / Meg Fuschetti Production Director / Mari Rodriguez (603) 891-9193 • Marketing Communication Manager / Kristen Jones (603) 891-9425 • Ad Traffic Manager / Jackie Linker (918) 832-9314 • ________________ PRINTED IN THE USA GST NO. 126813153 Publications Mail Agreement Number 40052420 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  7. 7. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F Are you ready to feel the speed? Super fast testing with the WireScope Pro LAN Cabling Tester Agilent’s WireScope Pro tester sweeps a full 1GHz in a few seconds, boosting your test speed to new industry leading Cat 6A and Cat 7 autotest times of 9 seconds. It also accelerates your copper and fiber testing with dual- wavelength fiber probes, the elimination of field calibration, and a new auto-increment capability. The WireScope Pro tester is the only handheld to provide Alien Crosstalk (AXT) measurements simultaneously on multiple ‘exciter’ cables, as well as produce final results on the spot, so you can quickly handle any future AXT field testing requirements. Alternative approaches could take hours to complete and require PC post processing to see the results. With simple software upgrades and a robust hardware platform operating at 1 GHz frequency, you’ll save on the cost of test because you’ll stay state-of-the-art for many years, eliminating the need to buy new testers every year or two. u.s. 1-800-829-4444, ext. 5465 Experience the speed of the WireScope Pro tester now at canada 1-877-894-4414, ext. 5465 or by talking to one of our _____________________ _________________________ engineers by calling our 800 #s. © Agilent Technologies, Inc. 2006 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  8. 8. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F Your network’s health is everything R ecently, I had occasion to A doctor had ordered radiologi- department will. spend time in a special-care cal tests on a patient and required But even more striking was the unit at a hospital—not as a the results “stat.” Now, I have seen doctor’s exasperation at being put patient, but visiting for many hours enough episodes of ER (I’ll never on infinite hold twice, not by some with a loved one who was a patient in admit to watching Grey’s Anatomy) automated answering system, but the unit. Because all medical matters to know that “stat” means right away. by a real person. Then it dawned on were resolved positively and this Two hours later, the doctor could me that the doctor, along with all her member of my family came home find no results in the hospital’s data colleagues, relies first and foremost healthy, I was able to reflect on my network. So, she called the radiology on the data network for the infor- time in that hospital with some department desk, demanding to mation she needs. And there’s good practicality rather than completely know why so much time had elapsed reason for this doctor to look for in- emotionally. with no answers. The individual who formation in a database long before And one or two answered the phone in the radiology looking for it from an individual. of my observations department put the doctor on hold— We live in a fully connected world made me think and kept her there. Frustrated, the whose human element is almost about networking doctor called the desk again and always disconnected. We’ve had cell and cabling. made the same demand. Unbeliev- phones forever and through Black- But fi rst things ably, the same thing happened: on berries have been able to get our first. While a visi- hold forever. e-mail from just about anywhere. tor at the hospital, I So, the situation got escalated to the But how many phone messages go was the beneficiary top-ranking member of the radiology unreturned? How many e-mails of many comforts and accommoda- department. At that time, the doctor unanswered? The digital signals do tions, one of which was the opportu- learned the results were, in fact, avail- their jobs by getting information nity to spend time at my loved one’s able; the head of radiology read the from one point to another; it’s the bedside any time of the day or night. results to the doctor over the phone, people who have become the black As such, I witnessed more inner and the doctor went about caring for hole. I have been a frustrated mes- workings of that environment than her patient based on the information sage-sender at times. I have also been I ever imagined I would. That means she had just received. In an environ- a guilty non-returner of correspon- I saw patients in various stages ment of such immediacy, the doctor dence. So, if I’m going to point a finger of distress, and observed the quick quickly moved on to the next order anywhere, it will point to me first. (and I don’t mind saying heroic) of business. She did not have the lux- The experience made me realize actions of doctors and nurses who ury of stopping to either ponder or that many of the information sys- literally saved at least one life in complain about the communication tems you build and use today have front of my eyes. breakdown that had just taken place. become more relied-upon than So, here are these health-care pro- I eavesdropped on this event with people. Scary. But not nearly as scary viders working around the clock to interest because, after all, my loved as sitting by a loved one’s hospital maintain the health of the patients in one could have been the next one for bed for a few days. their care, or to restore their patients’ whom radiological test results were health. They don’t need, and won’t needed stat. One thing that occurred tolerate, something like a network to me was the information that was interruption getting in their way. But supposed to be in the hospital’s da- they almost did while I was watching. ta network and available to the doc- While I’m sure there’s much more to tor, was not. A network problem? PATRICK McLAUGHLIN Mc the story than I saw and heard, I’ll Could be. Cabling-related? I’ll never Chief Editor retell it from my vantage point. know, but hopefully the hospital’s IT 6 ■ July 2007 ■ Cabling Installation & Maintenance C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  9. 9. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F How many tools do you use to Certify, Identify, Configure & Document your Ethernet network? (That’s too many!) Validator-NT ™ The All-in-One Network Management Tool CERTIFY individual Ethernet cable runs up to 1 Gigabit Speed per IEEE802.3 specifications. Test for TIA568 Interconnect problems. Determine fault locations, cable length and delay or noise 4" color LCD screen conditions. Produce and print cable test schedules Lithium/ion battery and cable test results. Qualify lines for VoIP usage. provides 8 continuous hours of use IDENTIFY active components of your network on Unlimited flash the other end of the cable. Identify all types of equipment card memory and port service discovery with advertised speed ratings and DHCP negotiation. Access IP addresses, ping equipment and flash hubs/switches for positive port location. CONFIGURE links between nodes at Gigabit speed. Check IP addresses on netmask, Gateway/routers and domain name servers. Confirm links between equipment for changes or upgrades. DOCUMENT the network with the included powerful Plan-Um™ software. Create layouts of offices/premises or import existing Visio/AutoCAD drawings. Show cables and equipment they connect to in physical locations. Print out layouts and corresponding Cable Test Schedules. The Network Tool section of Plan-Um™ allows you to create a complete topology layout of the network for on-site reference, showing connections, equipment and cable pathways. You can add notes to each component of the network for future add, changes, and move legacy information. Powerful Plan-Um™ Everything you need to Test, Trace software included and Tune your Ethernet Network. NT955 MSRP only $1495.00 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  10. 10. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F ____________________________ C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  11. 11. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F ‘Abandoned’ headaches begin early Editor’s note: This month, we bring you a slice of “Best of Ask Donna” from tion Systems, Section 820.2 defines years past. This column originally ran all the way back in February 2003, “Abandoned Coaxial Cable” as so why did we take it out of mothballs now? The first question-and-answer “Installed coaxial cable that is not ter- volley provides complementary information to another article running in minated at equipment other than a this issue (see pages 25 and 26). When reading, please note that the portions coaxial connector and not identified of the NEC discussed herein look essentially the same in the 2005 edition as for future use with a tag.” they do in the 2002 edition. Article 830 Network-Powered Then Donna finishes up with a question about the potential danger of lay- Broadband Communications Sys- ing unshielded twisted-pair cables too neatly. It struck me as an eerie fore- tems, Section 830.2 defines “Aban- shadowing of what the industry has been dealing with for the past couple doned Network-Powered Broadband years. I hope you enjoy this month’s “Best of Ask Donna” and, even more Communications importantly, find it useful.—Ed. Cable” as “Installed network-powered Q: I have a quick question. Could and Power-Limited Circuits, Sec- broadband com- I get the exact wording of what tion 725.2 defines “Abandoned Class munications cable the National Electrical Code 2002 2, Class 3, and PLTC Cable” as “in- that is not termi- states concerning abandoned stalled Class 2, Class 3, and PLTC nated at equip- cables in the plenum? cable that is not terminated at equip- ment other than a Brent Clements ment and not identified for future connector and not Rice University use with a tag.” identified for future Houston, TX Article 760 Fire Alarm Systems, use with a tag.” Section 760.2 defines “Abandoned So, what is this telling us? No- A: The question may be quick, but Fire Alarm Cable” as “Installed fire tice the common thread, “and not the answer certainly is not. Let’s alarm cable that is not terminated identified for future use with a tag.” begin with the definitions of aban- at equipment other than a connec- Any cable addressed in these specific doned cable. In NEC 2002, there tor and not identified for future use articles that is “tagged for future use” are seven definitions for abandoned with a tag.” is not abandoned cable. cable. Ironically, none are in Article Article 770 Optical Fiber Cables In some cases, having a connec- 100, the section on definitions (yet). and Raceways, Section 770.2 defines tor terminated at one end (audio dis- Article 640 Audio Signal Pro- “Abandoned Optical Fiber Cable” as tribution cable; Class 2, Class 3, and cessing, Amplification, and Repro- “Installed optical fiber cable that is PLTC Cable) or both ends (commu- duction Equipment, Section 640.2 not terminated at equipment other nications cable) of the cable means defines “Abandoned Audio Distri- than a connector and not identified that it is not abandoned cable. bution Cable” as “installed audio for future use with a tag.” While in other cases, having the distribution cable that is not termi- Article 800 Communications Cir- cable connected to equipment that nated at equipment and not identi- cuits, Section 800.2 defines “Aban- is not a connector (fire alarm ca- fied for future use with a tag.” doned Communications Cable” as ble; optical fiber cable; coaxial ca- Article 725 Class 1, Class 2, and “Installed communications cable that ble; network-powered broadband Class 3 Remote-Control, Signaling, is not terminated at both ends at a communications cable) means that connector or other equipment and it is not an abandoned cable. In NEC DONNA BALLAST is BICSI’s standards s standards not identified for future use with speak, a “connector” is “equipment,” representative, and a BICSI registered and a BICSI registered communications distribution designer (RCDD). distribution designer a tag.” and that is why the “equipment other (RCDD). Send your question tovia e-mail: Send your questions to Donna Donna at: Article 820 Community Anten- than a connector” verbiage is used. na Television and Radio Distribu- Most Sections [640.3(A); ➤ Cabling Installation & Maintenance ■ July 2007 ■ 9 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  12. 12. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F 725.3(B); 760.3(A); 770.3(A); 800.52(B); You asked specifically about ple- Q: I was reviewing the discussion on the 820.3; 830(A)] only address the “acces- num spaces, but the same text applies BICSI Public Forum about laying cables sible portion” of an abandoned cable to plenum, riser, and hollow spaces in parallel to each other in a fi xed physical as “not be permitted to remain.” Arti- the building. If it is “abandoned” and relationship. I noticed that one comment cle 100 defines “Accessible (as applied to “accessible,” take it out. said that the European norm addresses wiring methods)” as “Capable of being Seven definitions for almost the same it to some degree. Do you know if any removed or exposed without damag- term is a lot, even for the NFPA. So, for of the U.S. standards have intentions to ing the building structure or finish or NEC 2005 the International Brother- address it? I have a client in New Jersey, not permanently closed in by the struc- hood of Electrical Workers Codes and with a large data center, that is asking ture or fi nish of the building.” … So, Standards Committee is proposing to me for input. At present they are laying this is not a surgical removal in a fin- delete the current seven to add a new large bundles of cables into cable trays ished space. But if the entire area of the definition to Article 100, which would and they want the cables combed as they building is undergoing demolition for read: “Abandoned Cable. Installed are installed. I told them I would check remodeling, then all of the cable should cable that is not terminated at both and let them know. be accessible and removed. ends at equipment and not identified for Bobby Ashton, Jr., And then there is Article 645—the future use with a tag.” But so far the RCDD/LAN Specialist one that did not bother to uniquely other “stakeholders,” who carefully South Windsor, CT define “abandoned cable,” which is crafted the various definitions in their only concerned with abandoned cable respective Articles, are not supportive A: Intentions, yes. At the TIA TR-42.1 that is not contained in metal raceway. of this “one-size-fits-all” approach. February 2002 meeting, a presentation So, metal raceways full of dead cable It is going to be an interesting couple (TR 42.1-2002-013) was made, which ref- under raised floors in data centers are of years. erenced a list of contributions, previously not a concern? submitted to either the TR-42.7 Tele- PANDUIT introduces the affordable and powerful COUGAR ™ LS9 Hand-Held Thermal Transfer Printer ■ Economical identification system provides premium quality solutions at the lowest installed cost ■ Prints a wide variety of continuous tapes for marking of cables, patch panels, faceplates and other network applications ■ Legends can be easily aligned with ports on patch panels and faceplates, eliminating the need for manual spacing and guesswork ■ Cut-to-length functionality eliminates label waste and label trimming labor ■ Partial cut feature available to provide tear-apart strips of labels ■ P1 ™ Label Cassette contains integrated memory device for automatic formatting, recall of last legend used, and number of labels remaining in the cassette ■ Fast-loading label cassette includes both label material and ribbon to make changing labels easy PANDUIT offers a broad range of economical identification products that aid in TIA/EIA-606-A compliance including labels, labeling software, and printers. Visit us at Contact Customer Service by email: or by phone: 800-777-3300 and reference ad # p922 Cable Network Partial Cut Strip P1 ™ Label Cassette Marking Components of Labels C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  13. 13. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F communications Copper Cabling Sub- and the pathway is not overfilled, then have seen use seven cables—six disturb- committee or the Cable Working Group, “alien crosstalk” should be one less net- ers and one victim cable. That would dating from 1997 through 2002. Each of work anomaly you have to address. mean seven sets of field test instruments these contributions had addressed some And what about testing? While your in use at the same time to test one cable negative effect on the transmission per- network can certainly suffer from the link. And there are currently no pass/fail formance of category UTP cabling effects, measuring alien crosstalk is not limits proposed or set. caused by bundling or other similar something you want to attempt in the My advice: loosen up and avoid the cabling installation practices. field. Most measurement models that I problem. TR-42.1-2002-013 suggested that, based on these contributions, a Study Group be formed to develop informa- tion on the expected variance in trans- mission performance of cables that are installed in close proximity. TR-42.1-2002-013 further proposed that once the work was completed and validated, it would be drafted as a matrix, and published as an informative Annex to TIA/EIA-568B.1. The matrix would include alien NEXT and FEXT for Cat- egory 5e and Category 6 cables that are tie-wrapped at specified intervals, cables installed in a tray with 50% fi ll, cables installed in a conduit with 40% fill, and cables suspended on J-hooks. Meanwhile, we will have to contin- ue to scare our clients suffering from “overneatness tendencies” using threats of the dreaded “alien crosstalk.” You are welcome to use the following. It has worked for me in the past. Cabling systems and network hard- ware are designed to handle predict- What’s at the core of your fiber? able noise, like NEXT and FEXT, which comes from within the same cable. This is why when you remove the sheath from a twisted-pair cable, each of the pairs is twisted at a different rate. But when UTP cables of the same con- struction are neatly dressed and packed, Chances are you don’t know. Some fiber manufacturers you are inviting trouble. You are creating don’t specify bandwidth in the critical center region of a quasi field-manufactured hybrid cable, the fiber. But when you select OFS’ LaserWave® OM3 because the twists are the same in each of fiber, you get outstanding performance right down to the neighboring cables. This creates un- the core. LaserWave fiber delivers DMD specified in the predictable noise between neighboring 0 – 5 micron range and up to twice the bandwidth for lasers that launch power in the fiber’s center. Enjoy fast, cables; the noise is called alien crosstalk. reliable transmission and easier connectivity. To learn more, And the neater the cables are laid, and the ask your cabler about OFS or visit closer you pack them together, the more likely you are to experience the problem. If the UTP cables are randomly laid Cabling Installation & Maintenance ■ July 2007 ■ 11 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  14. 14. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F ALL HAIL THE NEW KING OF CARGO. INTRODUCING THE ALL-NEW 2007 DODGE SPRINTER > Dodge Sprinter is the most versatile commercial van on the market* > Combine the 3500 Extended Cargo Van with a 170-inch wheelbase and the available Mega Roof and you get best-in-class* cargo capacity of 600 cu ft, up to 89% more than GM competitors and up to 118% more than Ford > Towing up to 5,000 lb† > Combine 3500’s 144-inch wheelbase with High Roof for best-in-class* payload of up to 5,570 lb, up to 32% more than Ford and up to 34% more than GM’s 3500 cargo vans. For more info, visit, or call 800-4ADODGE. *Based on Automotive News classification. †When properly equipped. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  15. 15. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F Chrysler Financial is a business unit of DaimlerChrysler Financial Services. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  16. 16. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F Mohawk’s pre-terminated fiber optic Plug’n Play solutions combine ease of installation with the flexibility to work with any corresponding fiber cassette. Whether long runs or short runs, Mohawk’s Plug’n Play fiber solutions complement data center performance with its compact cable size and maximum flexibility. Features and Benefits: • Pre-terminated cables for premium performance. • Small diameter and bend radius for installation in high density environments. • The MPO terminations allow the cables to plug into any corresponding fiber cassette. • Compliant to TIA-568-C.3. MOHAWK For more information or a copy of our Application Note visit www.mohawk-cable or call 800-422-9961. Cabling Excellence for Open Architecture C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  17. 17. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F design The myths and realities of shielded, screened cabling A global standard since the 1980s, screened and shielded twisted-pair cop- per cabling varieties are still a mainstay Potential users must separate fact from fiction concerning noise immunity, grounding, and the antenna effect. in some markets. While many other mar- kets have migrated largely to unshielded twisted-pair not yet be realized by early-generation twisted-pair design (UTP) cables, the recent ratification of the 10GBase- and manufacturing capability. It is not surprising that this T standard for 10-Gbit/sec Ethernet over copper has robust cabling type still supports some buildings today. re-established the commercial viability of screened and By 1990, however, LAN industry experts began to recog- shielded systems, and has fueled greater adoption of nize Ethernet’s performance and reliability advantages over these systems in markets that previously were UTP-centric. LAN noise sources In this competitive landscape, H many confusing and often con- Ve E tradictory messages are finding l their way to the marketplace. This article addresses common questions, issues, and miscon- ceptions regarding screened and h Vd shielded cabling. From Token Ring to Ethernet Vg When LAN cabling emerged in Equipment Interconnect Work area outlet End-user device the 1980s to support the first Source: Siemon computer networks in commer- cial building space, the networks typically deployed IBM This setup shows the three sources of noise for LAN cabling sys- Token Ring transmission, which was standardized as tems. Differential noise (Vd) is induced from an adjacent twisted- IEEE 802.5 in 1985. Cabling for Token Ring networks pair or balanced cable; environmental noise (Ve) is induced by was IBM Type 1 cable—consisting of two loosely twist- an external electromagnetic field; and ground loop noise (Vg) is ed, foil-shielded, 150-Ω pairs surrounded by an overall induced by a difference in potential between conductor ends. braid—mated to unique hermaphroditic connectors. This cabling was an optimum choice for support of first- Token Ring. Concurrently, twisted-pair design and man- generation LAN topologies. Its design took advantage of ufacturing capabilities had progressed to the point where the twisted-pair transmission protocol’s ability to individual foils were no longer required to provide inter- maximize distance (Token Ring served distances up to nal crosstalk isolation, and overall shields were not neces- 100 meters) and data rates using cost-effective transceivers. sary to provide immunity against outside noise sources in The foils and braid improved crosstalk and electromagnet- the 10Base-T and 100Base-T bands of operation. ic compatibility (EMC) performance to levels that could Publication of the 10Base-T application in 1990, and the first edition TIA/EIA-568 cabling standard the fol- VALERIE RYBINSKI is global sales engineer with Siemon ( lowing year, in conjunction with the lower cost as- ➤ Cabling Installation & Maintenance ■ July 2007 ■ 15 C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue Next Page EMaGS B F
  18. 18. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F sociated with UTP cabling, firmly established UTP as the While this bandwidth provides more than sufficient noise medium of choice for new LAN networks. immunity for such applications as 100Base-T and 1000Base-T, Shannon Capacity modeling demonstrates that this level pro- Balancing act vides no headroom to the minimum 10GBase-T noise immu- The benefit of specifying balanced twisted-pair cabling for nity requirements. The use of shielding, however, data transmission is clearly demonstrated by examining the significantly improves noise immunity, doubles the available types of signals present in building environments. Electrical Shannon Capacity, and substantially increases practical oper- signals can propagate in either common mode or differential ating bandwidths for future applications. (i.e., “balanced”) mode. Common mode describes a signal scheme between two con- Noise and immunity ductors in which the voltage propagates in phase and is ref- Modal conversion is an effect of degraded twisted-pair signal bal- erenced to ground. Examples of common mode transmission ance above 30 MHz, which occurs when differential mode signals include DC circuits, building power, cable TV, heating/venti- convert to common mode signals, and vice versa. The conversion lation/air-conditioning (HVAC) circuits, and security devices. can adversely impact noise immunity from the environment Electromagnetic noise induced from disturbers, such as as well as contribute to crosstalk between pairs and balanced motors, transformers, fluorescent lights, and radio-frequency cables, and must be minimized whenever possible. Shielding (RF) sources, also propagates in common mode. Virtually can decrease the potential for modal conversion by limiting every signal and disturber type in the building environment noise coupled onto the twisted-pair from the environment. propagates in common mode, with one notable exception— All applications require positive signal-to-noise ratio (SNR) twisted-pair cabling, which is optimized for balanced, or dif- margins to transmit within allocated bit error rate (BER) ferential mode, transmission. levels. This means that the data signal being transmitted must Differential mode transmission refers to two signals that have be of greater magnitude than all of the combined noise dis- equal magnitudes, but are 180° out of phase, and that propa- turbers coupled onto the transmission line—i.e., the struc- gate over two conductors of a twisted pair. In a balanced cir- tured cabling. cuit, two signals are referenced to each other rather than one Noise can be coupled onto twisted-pair cabling in any or signal being referenced to ground. There is no ground con- all of three ways. nection in a balanced circuit and, as a result, these types of • Differential noise: Noise induced from an adjacent twist- circuits are inherently immune to interference from most com- ed-pair or balanced cable; mon mode noise disturbers. • Environmental noise: Noise induced by an external elec- In theory, common mode noise couples equally onto each tromagnetic field; conductor of a perfectly balanced twisted-pair. Differen- • Ground loop noise: Noise induced by a difference in poten- tial mode transceivers detect the difference in peak-to-peak tial between conductor ends. magnitude between the two signals on a twisted pair by per- Different applications have varying sensitivity to interfer- forming a subtraction operation. In a perfectly balanced ence from these three noise sources, depending upon their cabling system, the induced common mode signal would capabilities. For example, the 10GBase-T application is com- appear as two equal voltages that are simply subtracted out by monly recognized to be extremely sensitive to alien crosstalk the transceiver, thereby resulting in perfect noise immunity. (differential mode cable-to-cable coupling) because its digi- In the real world, however, twisted-pair cables are not per- tal signal processing (DSP) capability electronically cancels fectly balanced, and their limitations must be understood by internal pair-to-pair crosstalk within each channel. Unlike application developers and system specifiers. pair-to-pair crosstalk, alien crosstalk cannot be cancelled by TIA and ISO/IEC committees take extreme care in speci- DSP. Conversely, because the magnitude of alien crosstalk is fying balance parameters, such as transverse conversion loss very small compared to pair-to-pair crosstalk, the presence of (TCL), transverse converse transfer loss (TCTL), and equal- alien crosstalk minimally impacts the performance of other level transverse converse transfer loss (ELTCTL) in their applications, such as 100Base-T and 1000Base-T, that employ standards for higher-grade (Category 6 and above) struc- partial or no crosstalk-cancelling algorithms. tured cabling. By examining the performance limits for these EMC describes both a system’s susceptibility to interfer- parameters and noting when they start to approach the noise ence from, and potential to disturb, outside sources. It is an isolation tolerance required by various Ethernet applica- important indicator of a system’s ability to co-exist with other tions, it becomes clear that the practical operating bandwidth electronic/electrical devices. Noise immunity and emissions per- (defined by acceptable levels of common mode noise immu- formance is reciprocal, meaning that the cabling system’s abil- nity due to balance) is approximately 30 MHz. ity to maintain immunity to interference is proportional ➤ 16 ■ July 2007 ■ Cabling Installation & Maintenance C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  19. 19. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F copper-to-fiber media converters that extend your network exactly where and when you need it. Transition Networks sharpens your ability to do smart business with modular conversion solutions that give you the control to expand your network by user, distance, or protocol. Put us between your copper and fiber for a secure and smooth response to your networking issues. Our media converters economically accommodate multiple protocols, platforms and interfaces. Contact Transition Networks and take dead aim at doing business even better. Transition Networks take performance above and beyond expectations with every product we make.We are the simple, seamless and practical solution to copper-fibre conversion; accommodating multiple protocols, platforms and interfaces. Expand, extend and expect far more from Transition Networks. Contact us today and plan to go farther. 800-526-9267 transition networks for me. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  20. 20. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F to the system’s potential to radiate. Interestingly, while the outermost conductive element of the cabling—the conduc- unnecessary emphasis is placed on immunity considerations, tors themselves in a UTP environment, and the overall screen/ it is understood that structured cabling systems do not radi- shield in a screened/fully shielded environment. ate or interfere with other equipment or systems in the tele- Again, through the means of calculations, what becomes communications environment. readily apparent is that the common mode impedance is not Here’s a more detailed look at the various noise disturbers: very well controlled in UTP environments. This impedance Differential noise disturbers. Alien crosstalk and internal depends on factors such as distance from metallic raceways, pair-to-pair crosstalk are examples, and must be minimized metallic structures surrounding the pairs, use of non-metallic through proper cabling-system design. Susceptibility to inter- raceways, and termination location. Conversely, this common ference from differential mode sources is dependent upon sys- mode impedance is well defined and controlled in screened/ tem balance and can be improved by isolating or separating shielded cabling environments. conductors that are interfering with each other. Cabling with Importantly, the overall susceptibility of twisted-pair improved balance—Category 6 and above—exhibits better cables to electric field disturbance depends on both the bal- internal crosstalk and alien crosstalk performance. Because no ance performance of the cabling and the presence of a screen cable is perfectly balanced, strategies such as using dielectric or shield. Well-balanced cables (Category 6 and above) should material to separate conductors or using metal foil to isolate be immune to electromagnetic interference up to 30 MHz. The conductors are employed to further improve crosstalk perfor- presence of a shield or screen is necessary to avoid electromag- mance. For example, Category 6A F/UTP cabling is proven to netic interference at higher frequencies, which is an especially have substantially superior alien crosstalk performance than critical consideration for next-generation applications. Category 6A UTP cabling because its overall foil construction For example, it is reasonable to model that an emerging reduces alien crosstalk to virtually zero. Category 7 S/FTP is application using DSP techniques will require a minimum proven to have substantially superior pair-to-pair and alien SNR of 20 dB at 100 MHz. Because the minimum isolation crosstalk performance than any Category 6A cabling design yielded by balance alone is also 20 dB at 100 MHz, the addition because its individual foiled twisted-pair construction reduc- of a screen or shield is necessary to ensure this application has es pair-to-pair and alien crosstalk coupling to virtually zero. sufficient noise immunity headroom for operation. These superior crosstalk levels could not be achieved solely Ground loops. These develop when there is more than one through compliant balance performance. ground connection, and the difference in common mode volt- Environmental noise disturbers. Environmental noise age potential at these ground connections induces noise on the is electromagnetic noise made up of magnetic fields gener- cabling. It is a misconception that common mode noise from ated by inductive coupling, and electric fields generated by ground loops can only appear on screens and shields; this noise capacitive coupling. Magnetic field coupling occurs at low regularly appears on the twisted pairs as well. A key point about frequencies, such as 50 or 60 Hz, where the balance of the the voltage generated by ground loops is that its waveform is cabling system is more than sufficient to ensure immunity. Its directly related to the profi le of the building’s alternating impact can be ignored for all types of balanced cabling. Elec- current (AC) power. In the United States, the primary noise tric fields, however, can produce common mode voltages on frequency is 60 Hz and its related harmonic, which is often balanced cables depending on their frequency. The magni- referred to as AC “hum.” In other regions of the world, the pri- tude of the voltage induced can be modeled, assuming that the mary noise frequency is 50 Hz and its related harmonic. cabling system is susceptible to interference in the same Because each twisted pair is connected to a balun transformer manner as a loop antenna. and common mode noise rejection circuitry at both ends of Mathematical formulas demonstrate that a 60-Hz signal the circuit—the network interface card (NIC) and the network results in an electric field disturbance that can only be mea- equipment—differences in the turn ratios and common mode sured in the thousands-of-mV (millivolt) range, while sources ground impedances can result in common mode noise. The operating in the MHz range can generate a fairly large electric magnitude of the induced noise on the twisted pairs can be field disturbance. For reference, 3 Volts/meter (V/m) is consid- reduced, but not eliminated, through the use of common mode ered to be a reasonable approximation of the average electric terminations, chokes, and filters within the equipment. field present in a light industrial/commercial environment, and Ground loops induced on the screen/shield typically 10 V/m is considered to be a reasonable approximation of the occur because of a difference in potential between the ground average electric field present in an industrial environment. connection at the telecommunications grounding busbar The loop area is the one variable that impacts the magnitude (TGB) and the building ground connection provided through of the voltage coupled by the electric field. Common mode cur- the network equipment chassis at the work-area end of the rents generated by an electric field induce unwanted signals on cabling. Note that it is not mandatory for equipment ➤ 18 ■ July 2007 ■ Cabling Installation & Maintenance C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F
  21. 21. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F 1990s 1970s Shielded “Vampire” Modular Tap Jack 1980s 4 Position Data Connector Follow The Leader In Shielded Technology The new AMP-TWIST Jack is our latest shielded product evolution. It can be terminated in about 90 seconds, quicker and more reliably than any similar product on the market. Tyco Electronics has always been forward, have been the leading Proceed With Confidence on the cutting edge of shielded advocate for shielded technology If you are considering upgrading to technology. We have been designing across the globe. a 10 G solution, then come to the and manufacturing quality shielded brand that knows shielded best! Visit communications products for more Tyco Electronics has always believed to see why than three decades. In fact, we what the industry is just now a high performance 10 G Shielded introduced our first fully shielded realizing, that a Shielded System is Cabling System from Tyco Electronics twisted pair cabling products in the by far the best choice for today’s is the best choice for your structured early ‘80s – and from that point 10 G performance requirements. cabling needs. Tyco Electronics, TE Logo, AMP AMP NETCONNECT, NETCONNECT, and AMP-TWIST are trademarks. , Other products, logos, and company names mentioned herein may be trademarks of their respective owners. C Previous Page A Installation 7Maintenance Contents Zoom In Zoom Out Front Cover Search Issue B Next Page EMaGS F