Recently, I found out that after conducting a series of tests, members of the Institute of Electrical and Electronics Engineers (IEEE; www.ieee.org) 802.3an working group-the individuals hammering out the final details of the 10-Gigabit Ethernet-over-copper specifications-have determined that 10GBase-T over the installed base of Category 6 cabling will be viable to a distance of 37 meters, not the 55 meters originally targeted.
My understanding is that if users take steps to mitigate alien crosstalk among bundled cables, Category 6 will be able to support 10GBase-T to longer distances. But that’s akin to saying you can run 100Base-T over 125 meters of Category 5. You probably can, if the cabling more than marginally meets the old Category 5 specs, was installed nearly perfectly, and has been maintained meticulously.
In some cases, I’m sure users have gotten Fast Ethernet throughput over more than 100 meters of Category 5. But the “holy grail” of standards says the maximum distance allowable is 100 meters.
Similarly, 37 is the number that will be tied in writing to 10GBase-T-over-Cat-6 in such documents as the Telecommunications Industry Association’s (TIA’s; www.tiaonline.org) Telecommunications Systems Bulletin, TSB-155 Additional Guidelines for 4-Pair 100-Ω Category 6 Cabling for 10GBase-T.
While I’m sure this finding by the 802.3an group will have technical and business implications for users of Category 6 systems, when I found out about it, I didn’t like it because I’m not crazy about the number 37. I don’t think I have met anyone in my life whose favorite number is 37. It’s certainly not my favorite number.
Why does the number 37 not resonate with me? There are a few reasons. The year 1937 was not a particularly splendid one in United States history. With the nation’s unemployment above 14%, Amelia Earhart decided to get away from it all … and did. In a bad year all-around for flying, a dirigible named Hindenberg paid a visit to New Jersey in 1937.
Speaking of chemical reactions and bursting into flames, 37 is the atomic number of the element rubidium. Wikipedia tells me, “Rubidium is highly reactive, with properties … like igniting spontaneously in air.” So when you pop open a ceiling tile to unbundle some Category 6 cable, with the aim of reducing alien crosstalk, be sure to look out for that stray rubidium floating around up there.
But more than anything else, I don’t like 37 because it’s the number Bill Lee wore as a pitcher for my beloved Boston Red Sox. It’s not that I dislike him, it’s more that I’m still traumatized by a play I don’t even remember: the eephus pitch he threw to Tony Perez in Game 7 of the 1975 World Series, which Perez promptly hit out of the park to score the Cincinnati Reds’ first two runs of the game, leading to the Big Red Machine’s 4-3 victory in that game and the series.
As if that wasn’t bad enough, the next year, the Yankees’ Graig Nettles dislocated Lee’s pitching shoulder during a brawl between the two teams, and Lee never got his fastball back after that injury. And oh, by the way, guess which team won the World Series in 1937? That would be your 26-time World Series Champion New York Yankees. A favorite of many but, as I may have stated once or twice in this space, not my favorite team.
You would think that the glory of the Red Sox’ 2004 season would have washed away all the anguish of prior disappointments, but I guess not. My counselor says it will be a while longer before I fully come to grips with it. I was disappointed to hear that, too, because you know how many sessions I have been to already?
Thirty-seven.
All kidding aside, you too may need counseling of some sort if you have plans or aspirations to run 10GBase-T over your installed Category 6 cabling. Over the next few months, we will provide detailed information on mitigation techniques, as well as a host of other 10GBase-T issues, now that the IEEE standard is about to be finalized. As always, we aim to be one of your trusted information sources about critical communications issues.
PATRICK McLAUGHLIN
Chief Editor
[email protected]
