But as far as Mr. Flihan and others in New Jersey are concerned, that transition from a reliable service — one that has given them a sense of security all their lives — is not smooth at all. An array of state-sanctioned consumer advocacy groups, as well as AARP, have petitioned regulators to disallow the replacement of Mantoloking’s copper lines with Voice Link.

Not only will Voice Link not work if the power fails — a backup battery provides two hours of talking time, hardly reassuring to people battered by Sandy — but Verizon warns Voice Link users that calls to 911 under normal conditions might not go through because of network congestion. Medical devices that require periodic tests over phone lines, like many pacemakers, cannot transmit over Voice Link. Fax machines do not work over most wireless phone networks, including Voice Link. Neither do many home security systems, which depend on a copper phone line to connect to a response center.

“They told us this was the greatest thing in the world,” Mr. Flihan said. But he estimates that roughly 25 percent of the calls he makes through the Verizon Voice Link service do not go through the first time he dials, or sometimes the second or third. Occasionally, the call is interrupted by clicking sounds, and sometimes a third party’s voice can be heard on the line, Mr. Flihan said.

Verizon responded that it had offered to visit Mr. Flihan’s house to address the problems. Mr. Flihan said he had refused if Verizon would not bring back his landline. Overall, the company said that a vast majority of Voice Link customers in Mantoloking and elsewhere liked Voice Link, and if not, they could get phone service over cable television lines through Comcast or another provider.

The difference between wired and wireless, however, is a big one.

Traditional copper landlines use electric pulses to carry voice and data signals over a metal wire, which also carries power, so the phone works during a blackout. Fiber-optic lines are made of a thin glass filament and transmit voice and data at high speeds using pulses of light, but they cannot carry electricity and so do not work during a power failure without a battery. Cable television wires, which can also transmit telephone service, are made of copper, but they require a modem powered by electricity. Even cellphones require power at the cell tower, something that was knocked out during Sandy.

The phone companies point out that even among the households that still subscribe to a copper landline, most probably use cordless phones, which need electricity whether the house has a copper line or not.