The bottom line? Buy all the cabling performance you can even if it means downgrading that chair and deleting a couple of potlights.
March 1, 2007
Stop me if you’ve heard this one before — cabling technology has reached another performance platform, which exceeds the requirements of any technology in demand. More importantly, it is once again (still?) the unenviable task for those who must make such decisions to balance the desire for “future proof’ performance against the realities of today’s budget restraints.
As with each previous performance enhancement introduced, the decision is not an easy one. One thing that is certain is that with all the advancements and improvements to cabling systems over the years, there is yet to be a one-size-fits-all solution.
Of course, this refers to innovation and development in copper cabling. Fiber optic technology continues to be an alternate solution that addresses every issue except for cost. New cabling products have been introduced, which tune performance and allow bandwidth equal or superior to all copper systems over significantly greater distances. Subhead: A crosstalk cure
Completion of a new standard for Category 6A (Augmented) allows for the transmission of 10 Gigabit Ethernet over Unshielded Twisted Pair copper.
The restricting parameter for these systems is a previously unconsidered phenomenon known as alien crosstalk, which results from interference caused by adjacent cables.
The common cure is to maintain larger spaces between the cables, usually by increasing the cable size in some fashion to separate the conductors within cable-to-cable.
It is often noted that the “RJ45” connector is not the ideal platform for high performance data connections, however, it continues in general usage as result of its early adoption as the standard and a reluctance to deviate from it.
It would now seem that its shortcoming has as much to do with the physical space it requires as it does with electrical constraints to performance.
An interesting contradiction is that while server technology successively packs more and more processing power into smaller and smaller footprints, the cabling (copper) to support the associated higher bandwidth requirements is taking up greater amounts of space.
Fortunately, the size and the power and cooling requirements of these highly concentrated server configurations is leading to larger cabinets, which allow more cable management space.
Innovation has lead to alternate approaches such as an RJ21 interface (somewhat similar to the well known “amphenol” type connection), which have been available for some time, but whose time may have arrived as they are touted as the solution for high port densities desired in network electronics and which are currently thwarted by the traditional RJ45 connector.
These connections will condense 12 connections into a single connector taking up minimal space, and allow for even higher port density on electronics.
However, the systems are not available in support of 10 gig copper transmission so they would appear to require a performance/real estate tradeoff.
In defiance to our North American fixation with Unshielded Twisted Pair, some manufacturers are now offering shielded solutions to reach the 10-gigabit benchmark. These or similar solutions are popular in Europe and offer the advantage of reduced size as the shielding eliminates the alien crosstalk consideration and the need for larger cable designs.
The termination designs are much simplified compared to previous generations of shielded solutions. The drawbacks so far would seem to be cost and market acceptance.
Even fiber optic cabling systems have addressed space issues, with new smaller form factor connectors having been developed, and multiple strand single connectors, such as those designated MTP or MPO having potential to not just facilitate modular installation, but to reduce the interface size to the network electronics.
So what to do? Interestingly, the TIA-942 Telecommunications Infrastructure Standard for Data Centres issued in 2005 recommends Category 6 for horizontal copper cabling requirements.
To this day, there is no protocol based on or requiring Category 6 performance. The underlying message would appear to be that one should install the best available cabling systems, particularly in an environment like a data center likely to see the earliest adoption of successive equipment bandwidth enhancements.
It remains to be seen whether future revisions or addenda make recommendation of the new 6A standard.
The bottom line remains buy all the cabling performance you can. Downgrade that chair. Delete a couple of potlights. When you’re spending thousands of dollars on your modular furniture, doesn’t it make sense to spend a few dollars more on the technology that may facilitate the production of the person sitting there?
You don’t know what you’ll need it for, but isn’t that the point?
Rob Stevenson, RCDD/NTS Specialist, is Communications Division Manager at Guild Electric Ltd. in Toronto, and a member of CNS Magazine’s Editorial Advisory Board.