Frank Dickman, Anixter Inc.
It took three long years and more than 12 revisions before the Category 5E telecommunications cable standard was defined and made public last March. Now, the Telecommunications Industry Asso-ciation (TIA-Arlington, VA) is seeking to establish the specifications for the Category 6 channel-a proposed standard that's loosely defined and under considerable debate. And yet, Category 6-compliant products such as the cable listed in the Product Update table (see page 88) are offered for sale.
CommScope's UltraMedia Category 6 cable features the company's proprietary Isolator pair separator, designed to ensure accurate, full-duplex transmission in all four pairs.
How did Category 6 get out of the bag when it still hasn't been defined, and how should you assess what's compliant and what's not?
If the last 10 years have taught us anything, it's that telecommunications is a rapidly changing industry. Manufactur-ers create new products in an effort to create new markets, in which they may have an early advantage. In the world of telecommunications, increased data speeds generate the need for higher data-transmission standards.
But most of the same manufacturers of these new technologies are voting members of various industry standards committees, resulting in a conflicting dichotomy. In the United States, telecommunications standards are established by the TIA/Electronic Industries Alliance (EIA-Arlington, VA), under the auspices of the American National Standards Institute (ANSI), for the purpose of ensuring products from a variety of manufacturers will work together in a compatible and harmonious manner. Outside of the United States, other standards organizations hold sway, like the International Organization for Standardization/International Elec-trotechnical Commission (ISO/IEC-Geneva) as well as the European Committee for Electrotechnical Stan-dardization (CENELEC-Brussels), which establishes European guidelines.
Establishing guidelines
Some countries choose to adopt these standards, some adopt portions of various standards, and some establish their own. But the goal of all standards organizations is to establish guidelines that allow all manufacturers to participate in a market where the manufactured components are interoperable. Naturally, however, each manufacturer would like its proprietary product or unique solution to be voted upon and "standardized" as the only acceptable solution. This process leads to a considerable amount of divisive maneuvering before the market can agree upon a de facto standard. For this reason, committees take an extremely long time to establish standards and often lag far behind new technological developments.
For instance, the Category 5E standard, as defined in ANSI/TIA/EIA-568A-5, was published by the TIA through Global Engineering Docu-ments and made available in mid-March, three years after it was initially proposed. The TIA subcommittees are currently developing Category 6 specifications, a process that began in November 1997 as a joint unshielded-twisted-pair (UTP) proposal to ISO by Lucent Technologies (Murray Hill, NJ) and Anixter Inc. (Skokie, IL) to raise the bar in structured cabling transmission standards. The current TIA draft-the fifth-is incomplete and has been revised nearly every three months. It's estimated that a published, approved standard won't happen until at least January 2001.
What's the holdup? Since current Category 6 near-end crosstalk numbers are out-of-date, there will need to be a sixth draft before the next balloting in the fourth quarter of this year. At the same time, however, serious effort is being made to hurry the approval process along as the Cat 6 marketplace quickly becomes more saturated and sales personnel create discussions of a-believe it or not-Category 6E product.
But how can a manufacturer claim to offer Cat 6 (or greater) products when no standards exist?
First of all, the Cat 6 standard under development by the ISO is different from the proposed ANSI/TIA/EIA standard in the United States. Adding even more confusion, there are also various incomplete drafts of the proposed TIA/EIA Cat 6 standard, which, again, will differ from ISO Cat 6. And the National Electrical Manufacturers Association (NEMA-Rosslyn, VA) has a Cat 6 specification (WC66-1999) applicable to cable only, as does the Insulated Cable Engineers Association (ICEA- S. Yarmouth, MA).
Major manufacturers of cable, connectors, and test equipment have also made some form of contribution to the standard decision-making process, providing suggestions for consideration by TIA subcommittees. These drafts and submittals are not public documents and are not intended to be circulated by TIA members, and therefore, not readily available.
'Meets Cat 6'
Unfortunately, however, in the shorthand of the sales and marketing world, it's common to refer to current cabling products simply, as "meets Cat 6" or "is Cat 6-compliant." When Cat 5 was first standardized, it was common to hear some vendors refer to their products as Cat 5 when the product was never even addressed in the standard. At that point, Cat 5 simply became a magic word.
So, when a manufacturer presents its product as Cat 6, ask whether it is referring to a TIA Cat 6, ISO Cat 6, NEMA Cat 6, ICEA Cat 6, or some other Cat 6. Once the manufacturer answers that question, ask to see a copy of the standard, or a summary, so you can compare the electrical characteristics of the standard to those of the product offered. And don't be put off by reassurances or simple statements of "tested by an independent laboratory." Last November, a report by a well-known independent lab verified products as meeting Cat 6 channel performance-but under Draft 5. The TIA committee is working on Draft 6. Draft 5 was circulated in May 1999, but does not define electrical characteristics of ACR or PS-ACR for either the cable or the channel; therefore, it's incomplete and nonspecific of channel performance.
Why would a manufacturer claim its products are "tested" to a preliminary draft of a proposed standard still under consideration? What possible good can transpire to verify "channel performance" to a draft standard that doesn't fully specify it? On that basis, by the careful culling of available incomplete drafts, it's possible for anyone to certify just about anything.
The previously mentioned Cat 6E (Enhanced Cat 6) is a marketing invention. Since no TIA/EIA standard has been defined, references to Cat 6E imply the manufacturer feels that the cable is in some way enhanced and superior to a currently proposed Cat 6 standard. Such an elusive definition is somewhere between "ball lightning" and "will-o'-the-wisp."
Performance testing
To make sense of some of the marketing hype and confusion over Cat 6 and Cat 6E, Anixter maintains a Network Infrastructure Interopera-bility lab for testing products made by best-in-class manufacturers. The lab is staffed with professionals experienced in telecommunications testing, network design, and software development. In 1988, no uniform standard of performance existed for network cabling, and emerging applications were creating the need for increased bandwidth. Anixter contacted cable and equipment manufacturers, systems integrators, and major end users and concluded that it made sense to differentiate the performance of UTP cable for voice and data applications.
The results of the initial research and testing led to the publication of the first performance-level purchasing specification for communications cables-Anixter's Levels program. The specifications, which included Levels 1 through 3 (and later added 4 and 5), helped customers select the right level of electrical performance to run their applications. In early 1997, standards didn't exist for cable performance past 100 MHz, yet some technologies were beginning to exceed that requirement.
Meanwhile, over 150 different constructions of Category 5 cable were on the market, some of which performed only half as well as others. Working with leading manufacturers of structured cabling systems, Anixter began to define the performance characteristics of UTP cabling beyond 100 MHz by reaching for a performance mark that was more than twice the actual usable electrical bandwidth of some of the currently available Cat 5 cables.
The Anixter Levels program establishes three distinct Levels beyond Cat 5-Levels 5, 6, and 7-that help customers make intelligent purchasing decisions based on actual cable performance, particularly in instances when standards are out-of-date, pending approval, or nonexistent.
In summary, when comparing what's out there for products, it's important to remember that Category 6 does not yet exist. Manufacturers cannot claim that their product is Category 6-compliant when the standard hasn't been defined and published. A careful eye and attention to detail is the key in comparing the conflicting claims of marketing departments. It also helps to engage the assistance of trained technical support, like the RCDD and LAN specialists certified by BICSI. At the very least, make sure that your vendor is comparing its products to the most recent draft.
Frank Dickman is a senior technologist for Anixter Inc. (Skokie, IL) and votes on behalf of Anixter customer interests in various U.S. standards organizations.
Some refuse to jeopardize future network performance
Steve Smith
Until performance specifications for Category 6 are nailed down, some vendors say they refuse to buckle under the pressure of keeping up with competitors that are already marketing cable for which a standard has yet to be ratified.
"Sure, we have some cables that have been tested and meet the 'proposed' Cat 6 requirements," says Tri-Net Technology (City of Industry, CA) product manager Stanley Chan, "but we're not willing to push those products right now. I won't jeopardize my customers' future network performance with an uncertain and unsettled cabling standard."
Since it took two dozen drafts before Category 5E was approved, Chan and others believe Cat 6 approval "has a long way to go." "With the explosion of networking everywhere," Chan adds, "the pace of 'Category' cabling has not been met with the same speed of computer 'power' or megahertz. I realize the two sectors are very different, but it's very hard to separate one from the other. In my eyes, Cat 6 and everything beyond is great marketing hype by industry players with deep pockets."
John Pryma, vice president at Genesis Cable Systems LLC (Pleasant Prairie, WI), concurs: "We decided it may be premature to supply Category 6 performance parameters since the TIA standards are far from being finalized, and there are two differing performance specifications being debated in committee. We did not release a Category 5E cable product line until the standard was approved and have decided to follow the same policy with Category 6."
Being able to sell and support a sure thing, Chan adds, is vital for establishing customer satisfaction: "Our cables and products are Cat 5E-compliant, guaranteed. It really gets under my skin when I have customers coming to me asking for Cat 6 products because they saw a fancy ad somewhere."
But even when a Cat 6 standard is agreed upon, warns Bill Fetter, marketing manager for Krone Inc.'s (Englewood, CO) TrueNet end-to-end matched component system, buying industry-specified cable won't necessarily guarantee the promised performance. "We urge our customers to consider standards and individual component specifications as only one part of a complete decision on structured cabling," Fetter says. "Our research has shown standards-compliant components when combined in a system may not achieve optimal signal transmission over Ethernet. After all, if the cabling meets the standards but doesn't transmit data well, what good is it?"
In the "Product Update" table on page 88, performance categories listed were among those being considered for Category 6 Draft 5. The proposed standard is now in its sixth draft.