STRUCTURED CABLING: The Cat That’s Going to Dogs…

For any technology that came up in the postmodern era, there have been at
least two standards–an American, and, a vastly differing European one. All
industries bear testimony to this.

In the cellular industry, Europe loves to stick to the GSM standard, while
the US is the biggest breeding ground for CDMA. Likewise, in structured cabling,
Europe has always insisted upon shielded twisted pairs (STP) while the US has
gone whole hog for unshielded twisted pairs (UTP).

That’s America versus Europe. What about the rest of the world, especially
India? Well, as far as the cellular industry goes, the GSM-CDMA battle is still
fresh in memories of all.

Thankfully, the structured cabling industry, perhaps by virtue of default,
has managed to steer clear of any standards-related brawl.

Now, as the industry gears up for large-scale Cat 6 deployments, and the
possibility of Cat 7 becoming the next-in-line successor is raised, will things
be different?

That brings us to a more basic question–does Cat 7 have in it to become the
successor to Cat 6?

Cat 7 Prospects

The Telecommunications Industry Association (TIA) proposed the development
of Category 7 Class F cables. According to the proposal, vendors were expected
to develop fully shielded (overall shielded and individually shielded pairs)
twisted-pair cabling. This category of cables would be supported by an entirely
new interface design (i.e., plug and socket).

Many vendors came out with products that matched or surpassed TIA-proposed
specs. Since the very specs ensure that Cat 7 cables have to be STP, Europe is
the region where most of the deployments are happening, expectedly.

And what would be the future of Cat 7 in India? Bright, but for the two
developments that took place. One, the prices of fiber fell, continuously. Two,
there’s an advent of superior specs-packed Cat 6 products.

The drop in prices made fiber a viable option in the backbone. Fiber has the
capacity to carry much more data at a better speed as compared to copper. It
offers potentially unlimited bandwidth too. So organizations that already have a
Cat 5e or Cat 6 backbone in place, have been tempted to postpone an upgrade to
Cat 7 so that they can straight away move on to the fiber.

Postponing makes common business sense, given the oft-repeated statement that
structured cabling deployments are for 15—20 years. Once deployed, the
infrastructure can’t be dug up even if higher-speed cables arrive a year or
two down the line. Forget the investment, network managers are more worried
about the downtime.

Typically, a new standard tends to arrive every 3—5 years. For example, the
Cat 5e specification (TIA/EIA-568A-5) was officially ratified as a standard in
December 1999. Less than three years later, in June 2002, the Cat 6 ratification
took place.

Now, network managers can’t afford to change the cabling infrastructure
every 2—3 years. However, they can, with the aid of patchworks of course,
defer new deployments in anticipation of a technology that would take care of
the newer applications for a longer period of time.

So investment in a new technology will have to be evaluated against two
conditions: One, the existing infrastructure can no longer take care of the
majority of applications running on it. Two, the upgrade will remain the
dominant technology–and the one with maximum RoI–for a significant period of
time (3—5 years).

TIA-ratification is a key indicator for gauging the shelf life of a given
standard. It’s reflective of vendors’ confidence–and their seriousness–about
the standard.

Cat 7 ratification has not happened so far, and is unlikely to happen this
year. Vikas Pinjarkar, general manager (SCS), D-Link, says, "It may take at
least a couple of more years. As we would approach to 10 Gb and gradually to 40
Gb on copper we may require a proper earthing to the entire system which also
can support higher frequencies. Cat 7 may be a good option then."

But for how long? Pinjarkar doesn’t expect Cat 7 to have a long shelf life.
"More so, because Cat 6 is at present a very balanced solution which takes
care of almost all the applications. And vendors are already talking about
shipping their products for 10G over UTP," he says.

Cost is another factor that will work heavily against Cat 7. "Being a
STP construction, these cables are bound to be priced significantly higher than
Cat 6. Also, installation costs can turn out to be outrageous because skills are
so scarce in India for the STP variety. The bulkier and less flexible nature of
STP cables calls for a different approach in the design of pathways, and
grounding and termination techniques," Dilip Kumar, product and tech
manager (PremisNet), Krone, points out.

In fact, the long prevailing UTP culture has engraved habits that can spell
disaster for STP cables. For example, a single unterminated cable can create a
difference in ground potential, which in turn induces a current in the
shielding. This would result in a performance worse than in the case of
unshielded cabling. A loose STP end can in fact act like a giant antenna,
capturing and introducing significant amounts of noise into the cabling
infrastructure.

The promised advantages of Cat 7, which are many, begin to look far less
attractive in the light of the above.

The Fiber Threat

"Fiber is going great guns. The cost is going down drastically, thus
allowing users to afford a solution that can give almost unlimited bandwidth.
Looking at all these aspects, Cat 7 may not have a place in near future,"
says Pinjarkar.

Fiber, however, has a disadvantage in that the end equipments also need to
have a fiber support. The termination and maintenance of fiber is also a costly
affair. That makes the overall solution very costly.

"At present, the dominance of copper would be as high as 80 percent.
Even after 12 months, when Cat 5 would be mostly replaced by Cat 6, the ratio
between copper and fiber is unlikely to change, provided any specialized fiber
projects demand huge fiber deployments," Pinjarkar opines.

The message for enterprises is clear: Cat 6 continues to go strong in the
horizontal run. Fiber picks up in the backbone.

So a Cat 7 solution will have to be weighed against today’s Cat 6 products
on one hand and tomorrow’s fiber solutions on the other hand.

Isn’t Something Amiss?

Yes, what will happen to those higher-end apps that will just go jittery in
the absence of high data rate media? After all, the Cat 6 standard may not
support high frequencies, that certain apps would require.

Vendors are not oblivious of this problem and are trying to find a midway
solution to it. The concept that they are working on is quite simple–pack more
capabilities in their Cat 6 products and test them for as higher frequencies as
possible.

This development is feared by some industry quarters to further delay the
ratification of Cat 7, possibly even stall it. (All the more reason why one
should stay off Cat 7, at least for now.)

But will the genetically enhanced (it’s tempting to use the term) Cat 6
solutions adequately support the high-speed apps of the near, if not distant,
future? That’s the question for which network managers must demand an answer,
before okaying such a solution. Better still, they should test it.

To talk of the pricing, these solutions are expected to be positioned 20—25
percent higher than the existing Cat 6 solutions. "However, costs may come
down once the solutions take off and start selling in large quantities,"
says Kumar of D-Link.

There’s a catch though. These enhanced Cat 6 solutions may not work with
the existing connectors. That’s likely to increase the overall cost of
deployment. However, the good part is that these solutions won’t require any
special skill sets, because of their UTP characteristic.

It will be interesting to watch these enhanced Cat 6 solutions. Many vendors
have plans to launch their respective ranges in India shortly. Results of the
first such deployments will be interesting to watch.

Deepak Kumar