Congratulations! After an hours-long installation, your home is now connected to Verizon Communications Inc. (NYSE: VZ)'s FiOS network, and you have one of the fastest residential broadband hookups in the U.S. Say goodbye to that slow DSL connection.

Seriously, say goodbye -- because if you ever want to go back to DSL, there's a good chance you can't.

When Verizon connects the fiber line to your home during a FiOS installation, it is the company's standard practice that the technician cuts the copper connection from the street to your home. This leaves you with only a fiber line running into your house. Verizon says that customers prefer this over having a logjam of wires running through their property.

But what about those rare cases where someone only wants a cut-rate DSL connection and VOIP service. What happens when a formerly FiOS homeowner no longer wants to be a Verizon customer?

Though such a switch would probably be rare, there's a chance the copper line is gone for good. "We'd handle it on a case-by-case basis," says Mark Marchand, director of media relations at Verizon. "The goal would be that we want to keep them as a customer and we would do everything we could to reach an accord."

A customer fleeing from FiOS might not get far, as other competitive DSL providers rely on Verizon's copper infrastructure to reach customers in its territories.

Winning a former FiOS customer "would be very difficult to do, but its not impossible" said Arkady Goldinstein, CEO of AceDSL, a voice and DSL service provider in the Northeast. "You would have to ask the Verizon technician to leave the copper connection, but whether or not they do it depends on who ends up at your house."

AceDSL says there have been instances where Verizon has reconnected a copper line so that AceDSL could reach a former FiOS customer. The company says about 25 percent of all FiOS installations it sees still have copper going to the home, even though Verizon's usual procedure is to disconnect it.

With Verizon planning on passing 18 million homes with FiOS by the end of 2008, it would seem that a lot of copper lines are at risk of disappearing as more and more customers sign up. But that still isn't the death knell for the competitive carrier DSL business.

"FiOS has a negligible effect on the CLEC community," says Tom Nolle of CIMI Corp. "FiOS only extends what was already a deep fiber deployment." Nolle says companies like EarthLink and AceDSL have known for years of the movement towards fiber and that FCC regulations mandate that RBOCs are only obligated to maintain for wholesale the voice channel of any fiber access infrastructure.

For competitve DSL providers, the disappearing copper may not kill their business. But it probably won't help it either.

"The growth of Earthlink's broadband business has slowed from double digits to single digits, but I think they can maintain their current rate," says Vijay Singh, an analyst with Janco Partners Inc. Singh says Covad Communications Inc. 's expanding ADSL2 footprint shows there are still spots in the broadband market where CLECs and ISPs can do well.

— Raymond McConville, Reporter, Light Reading