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There is a great deal of speculation in the industry concerning network cabling's transition from Category 5 through Category 5e to Category 6 -- and perhaps even Category 7. Here is a look at the "whys and wherefores"as a new chapter unfolds.


May 1, 2000  


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AWAITING CATEGORY 6

WHEN IS IT COMING AND WHAT CAN WE EXPECT?

Over the next couple of years, network cabling will make the transition from Category 5 through 5e to Category 6. The first stage of that process — Category 5e replacing Category 5 — is already underway, and Category 6 will start taking over once the standard is formally ratified, which should happen in the first half of 2001.

“Category 5 has pretty much run out of speed,” says Navin Sabharwal, a senior analyst at research firm Allied Business Intelligence (ABI) Inc. in Oyster Bay, NY. Sabharwal expects sales of Category 5e cabling to overtake those of Category 5 some time this year. Even though they may not need it right away, Sabharwal says, customers will be choosing Category 5e cabling for new installations for the sake of “future-proofing” — to ensure that they will not have to re-cable again in a few years.

RAISING SOME QUESTIONS

The biggest reason Category 5e cable did not overtake Category 5 sooner was that the standard was still on the drawing board — at least officially. The Telecommunications Industry Association (TIA) only formally ratified the Category 5e standard this past winter. While there were products on the market before then that claimed to be compliant with the emerging standard, customers were wary of committing themselves before the standard was official.

The same concern surrounds Category 6 now. Even though a number of vendors offer products that comply with the Category 6 specifications — providing the performance that the specification currently requires — customers fear the standard is still a moving target. In some senses it certainly is, because some details remain to be worked out, and in the absence of clear rules, different vendors have taken different approaches.

Besides raising the question of whether vendors’ products will in fact fit the final standard, that means mixing and matching products from different vendors may not provide an overall package that performs up to Category 6 specifications.

“End users are wary of committing the additional money to buy a product that isn’t standardized,” says Rob Stevenson, communications division manager at Guild Electric Ltd. in Toronto. That fact feeds on itself to keep Category 6 installations low at the moment. Because customers are waiting for the standard to be complete, volumes are low, which in turn keeps prices high. Typically Category 6 cabling today costs 25 to 35 per cent more than Category 5e, Sabharwal says, and that makes customers even less eager to buy. Once the standard is complete, Stevenson predicts, customers will start buying more Category 6 cabling, which will increase manufacturers’ volumes. As volumes increase, prices will come down, which will encourage more customers to buy.

“Once (Category 6) does become a standard, most of your consultants will begin truly specifying it,” says John Schmidt, associate product manager for Enteraprise connectivity products at ADC Telecommunications, Inc. in Minneapolis, MN. In fact, he adds, Category 6 sales may well take off before the standard is formally ratified — once consultants and users are satisfied that the specifications are stable and ratification is a mere formality.

The net effect of this will be that before long Category 6 will do to Category 5e what 5e is already doing to Category 5. By 2005, ABI forecasts, Category 6 cabling will account for half of cable installations, with 5e down to 35 per cent and Category 5 accounting for only about four per cent. Most of the balance will be Category 7, a standard for shielded twisted pair that will capture a small segment of the North American market, but is not expected to move into the mainstream on this side of the Atlantic in the foreseeable future. (See story on p. 22). ABI’s figures are for the U.S. market, but the Canadian market will probably look similar.

IS CAT 6 BETTER?

Why Category 6? It is actually hard to say, except that in cable installations it makes sense to prepare for the future. Certainly it will provide added performance. Compared with Category 5e, Category 6 will provide greater bandwidth — up to at least 200 megahertz versus 100 megahertz — and improvements in attenuation, crosstalk and return loss. The net effect of all of this is that Category 6 will handle more data, more reliably, than Category 5e.

The TIA committee responsible for the Category 6 standard considered an alternate Category 6 standard that, chiefly by using better cable with 23- rather than 24-gauge conductors, would deliver 250-megahertz bandwidth and further reduce crosstalk. The alternate was dropped from the version of the standard now going out for a committee ballot, but some expect that the ballot results will force the committee to reconsider.

The current proposal will not handle transmissions up to 100 meters reliably at high temperatures, says Mark Maloney, senior consultant at Ehvert Technology Services in Toronto. “There are going to be objections from the end-user community,” he predicts.

Paul Kish, senior product manager at NORDX/CDT in Pointe Claire, PQ, and chair of the TIA’s TR-42 engineering committee, which deals with cabling standards, expects there will be a note in the standard about the need to use better cable or shorter runs in high-temperature conditions.

No matter how the fine points of the standard shake out, the big question is how that added capacity will be used. “What’s the application for Category 6 as yet is sort of undefined,” Sabharwal admits. But “some people are sort of looking ahead into the future and saying ‘I don’t know what’s going to happen.'”

Among the possibilities, Kish says, is a simpler way of implementing Gigabit Ethernet over twisted-pair cabling. Though the high-speed standard will work on Category 5e cabling, it is tricky — cabling that complies with the new standard might allow for other electronics to be simpler and deliver better results. Then there is the question of whether copper might ever be used for the 10-Gigabit Ethernet standard now being developed.

If the history of networking has one consistent theme, it is probably that the need for bandwidth keeps increasing. So it makes sense to install cabling with more capacity than you currently need. This will ensure that you don’t have to upgrade too soon. “People believe it will lengthen the life span of their cabling systems,” Stevenson explains.

That is good thinking, but the widespread desire to wait until the standard is final makes sense too. The simplest answer, where possible, might be to delay new installations until the Category 6 standard is clear. But that is not possible for everyone. So, what do you do if you really must run new cable now, but you want to make sure it will last as long as possible?

That depends partly on whether you expect to be on the bleeding edge of network technology — in which case it may be important a few years from now to have Category 6 cabling — or whether yours is more of an everyday, middle-of-the-pack network set-up, meaning that Category 5e might be good enough for years to come.

In the former case, Kish suggests you do your homework, take all the precautions you can, and jump in with a Category 6 installation. “If you’re really looking forward five years from now and you really see Category 6 as the way it’s going to go, what you can do when you make your purchasing decision is you can demand a certification and a warranty,” he says. “If I buy the best system available today, then I’m pretty confident that it’ll meet the final standard.”

Others echo that advice. A number of cabling equipment suppliers provide “application assurance” warranties that their Category 6 products will support anything designed to run on the Category 6 standard in the future. They say they can do this, even though the standard is not final, because they are designing their products to meet the maximum specifications anyone thinks might be in the finished standard.

“A vast majority of the information that is required to produce a good Category 6 syst
em does exist in the standard (today),” says Schmidt. He adds that choosing a manufacturer who is active on the standards committees, and therefore should be up to date on new developments, provides added security for buyers.

Read the fine print, though: the warranties may only apply if you use a single vendor’s products from end to end.

WIRING WITH CAT 6

Any time a new cabling standard comes along to replace an old one, an obvious question to ask is what installation issues will arise. With Category 6, the news is mostly good. Installing Category 6 wiring will not be much different than installing Category 5 or 5e — although it may be a bit more important to do things by the book. The rules are the same, Stevenson says. The only difference might be that failing to follow them exactly would more than likely get you into trouble. “If you’re not doing it right, you’re maybe going to get caught where you wouldn’t have before,” he says. The reason is simple: the more performance you squeeze out of cabling, the less forgiving it will be.

The Category 6 standard will be fundamentally compatible with 5 and 5e, says Sabharwal. Though some details of the standard remain to be worked out, it is clear that Category 6 will use the same RJ-45 connectors currently in use, as the wiring is not significantly different.

There is one added warning, though. While installing Category 6 should not be much more complex than installing the earlier standards (once the standard is clear), things are not quite that simple right now. Partly because the standard is not final, those vendors already offering products that they claim are Category 6 compliant may have got to the final result in different ways. Some of today’s Category 6 offerings are channel-compliant, meaning they deliver the overall results the standard is expected to require, but not component-compliant, meaning that each component in the system meets Category 6 specifications.

So, if you mix pieces from two or more vendors you really need to know what you are doing. “Some people will just look at the title and see Category 6,” Schmidt says, “and they’re not doing their homework.”

The same applies if you are installing new Category 6 wiring in combination with existing Category 5 or 5e cabling. It is important to ensure backward compatibility, and while that is certainly possible, Stevenson says, certain combinations of products could cause problems.

So, for the time being at least, it will be important to do careful research before beginning an installation. That is probably less true if you are buying everything from one vendor and installing it on its own, without any legacy equipment to worry about. Yet even then it probably pays to ask questions.

In addition, although Category 6 cabling uses the same connectors as Category 5e and earlier standards and, in principle, can be interconnected with earlier technology, this may not always work. The final standard will require backward compatibility, Kish says, but in some cases today’s Category 6 cabling systems will not support applications using existing equipment. The advice again is to ask a lot of questions and make no assumptions.CS

ASSESSING CATEGORY 7

WILL IT MAKE ITS MARK IN NORTH AMERICA?

Paul Kish, senior product manager at NORDX/CDT in Pointe Claire, PQ, is not holding his breath waiting for Category 7 cabling to become a big seller in Canada and the United States. “There is no interest in North America anyway in the Category 7 standard,” says Kish, who is also chair of the Telecommunications Industry Association (TIA) engineering committee concerned with cabling standards.

Yet Alex Smith, a telecommunications specialist and former consultant, is a Category 7 believer. “I would highly recommend a Category 7 system to a client because of the life cycle,” he says. In fact, Smith’s former employer, Toronto-area consulting firm Carinci Burt Rogers Engineering Inc., is planning to be the first Canadian organization to install Category 7 cabling.

Category 7 is an as-yet-incomplete standard for shielded twisted-pair. It would deliver at least three times the bandwidth of Category 6 unshielded cabling — from 600 megahertz to as high as one gigahertz. However, its future in North America is very uncertain.

CONTRASTING OPINIONS

It all comes down to a difference of opinion about shielded cabling: Europeans like it, North Americans do not. Nabin Sabharwal, senior analyst with Allied Business Intelligence Inc. (ABI) in Oyster Bay, NY, says European countries generally have stiffer regulations governing cabling, and to meet tougher restrictions on interference, European firms are more inclined to use shielded cable. American firms, on the other hand, are more concerned with cost and so favour unshielded cable. As a result, ABI’s projections call for Category 7 cabling to account for only 11 percent of U.S. installations by 2005, while Category 6 will account for half of these installations.

When it comes to meeting current and anticipated network needs, Category 6 will give performance “far in excess of anything that anyone can foresee right now,” says Rob Stevenson, communications division manager at Guild Electric Ltd. in Toronto, who describes Category 7 as a “European standard.”

Of course, Canada sometimes occupies a middle ground between the U.S. and Europe. Although network installations in this country are generally not much different from those in the U.S., perhaps the Canadian market will be a bit more receptive to Category 7 than the U.S. market.

Certainly Smith sees some value in it. As demands for network bandwidth increase, he says, many organizations have had to replace cabling more than once to keep up. Those with experience are getting tired of this and should welcome the chance to get ahead of the upgrade rat race.

Category 7 “should have a longer life cycle than we’ve seen,” Smith says. And while he admits that Category 7 wiring will cost more and be trickier to install than Category 6 wiring, he points out that because of its higher bandwidth, Category 7 might be seen as an alternative to optical fiber for some applications.

A FIBER ALTERNATIVE

When you consider Category 7 as an alternative to fiber, its advantages become more apparent. Smith points out that moving from twisted pair to fiber means replacing just about all of your network hardware, whereas with Category 7 cabling, you put in new shielded cable but can keep most other existing electronics, such as network interface cards and hubs.

This is not quite as simple as it sounds at first, because Category 7 — unlike Category 6 — is not expected to use the same RJ-45 connectors found in twisted-pair installations today. That is one reason why the move to Category 7 is a bit more daunting than a transition to Category 5e or 6. However, Smith says, there are adapter cords for connecting the proprietary Category 7 connectors to standard RJ-45 ports.

Eric Martin, market development manager at the Siemon Canada Co. in Markham, ON, which is handling the Category 7 installation for Carinci Burt Rogers, agrees that backward compatibility is a big plus for Category 7. He adds that besides compatibility with data networking hardware, the ability to connect telephones to the same cabling could be a plus. And the cost of the cabling itself, while not necessarily lower with Category 7 shielded twisted pair, will probably be comparable to the cost of fiber.

Still, Martin says, Category 7 will find a niche market at best in Canada. He believes Category 6 will be the de facto standard, with Category 7 used where the extra performance is important.

Another use for Category 7 might be in very noisy environments, such as on factory floors, says John Schmidt, associate product manager at ADC Telecommunications, Inc. in Minneapolis, MN. There, electrical interference may make shielding imperative.

INSTALLATION ISSUES

Category 7 cabling will be more difficult to install than earlier twisted-pair standards, and not just because it requires different connectors. Shielding makes the cables bul
kier, and they have to be installed carefully to avoid damage.

“The time it takes to install a cable is significantly greater,” says Martin. “If you don’t install it correctly,” Nabharwal agrees, “you’re pretty much going to render it useless.” In fact, Martin says he suspects Category 7 installation might be about as complicated as putting in fiber — which, he notes, is getting easier to terminate.

At present, there is no Category 7 standards effort under way in North America. North American cabling standards are the responsibility of the TIA, which is concentrating on Category 6. The work on Category 7 is in the hands of the International Standards Organization (ISO) and European standards groups, and is being driven by a handful of European countries, notably Germany.

“At least in the very near future I think you’ll find that unshielded twisted pair will still be the dominant solution in North America,” says Schmidt, “and it’ll be split fairly evenly between Category 5e and Category 6.”

The jury, as Martin says, is still out. At the moment, it seems unlikely that Category 7 cabling will occupy more than a minority share of the North American cabling market in the foreseeable future. It also appears that there will be at least some niche applications for Category 7, although Canadian companies doing business in Europe may find they have little choice but to deal with it.CS

Grant Buckler has written about information technology and telecommunications since 1980. He is now a freelance writer and editor living in Kingston, ON.


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