When dealing with fiber-optic data lines, there is white (or bright) fiber -- a line that is in use, there is dark-fiber -- a physical line but it is not being used at the time.
It seems that there is also black-fiber. From the Washington Post:
Metro Dig at Tysons Stirs Underground Intrigue
This part happens all the time: A construction crew putting up an office building in the heart of Tysons Corner a few years ago hit a fiber optic cable no one knew was there.
This part doesn't: Within moments, three black sport-utility vehicles drove up, a half-dozen men in suits jumped out and one said, "You just hit our line."
Whose line, you may ask? The guys in suits didn't say, recalled Aaron Georgelas, whose company, the Georgelas Group, was developing the Greensboro Corporate Center on Spring Hill Road. But Georgelas assumed that he was dealing with the federal government and that the cable in question was "black" wire -- a secure communications line used for some of the nation's most secretive intelligence-gathering operations.
"The construction manager was shocked," Georgelas recalled. "He had never seen a line get cut and people show up within seconds. Usually you've got to figure out whose line it is. To garner that kind of response that quickly was amazing."
And a bit more:
Georgelas, the developer whose company was overseeing the work in 2000 when the Chevrolet Suburbans drove up to the Greensboro Corporate Center, said he figured that the government was involved when an AT&T crew arrived the same day to fix the line, rather than waiting days. His opinion didn't change when AT&T tried to bill his company for the work but immediately backed down when his company balked.
"These lines are not cheap to move," Georgelas said. "They said, 'You owe us $300,000.' We said, 'Are you nuts?' "
The charges just disappeared.
Heh... I have administered T-1's bonded pairs and various OC-nnn lines before. If something happens, you will get a call within an hour or so.
With a standard home phone line or with cable broadband access, the company depends on the end user to report any service problems. By not having to put diagnostic equipment on every line (and pay people to monitor it), they save a lot of money and pass the savings over to you. When you sign up for a T-1, you are contracting to pay the company several hundred bucks/month but you are getting 24/7 live monitoring of line conditions and a guaranteed bandwidth. Last place I worked, I was moving some of the network wiring around and had unplugged the CSU for a few minutes to relocate it. This broke our connection with our provider and about ten minutes later, I got a phone call from them.
To have several people physically show up at the site of the break indicates a level of service that is several orders of magnitude greater. (The way they find the break is very cool geek-fu called Time Domain Reflectometry)
