Comcast (CMCSA) - Get Report left its shareholders hanging for another month.

John Alchin, chief financial officer of the nation's largest operator of cable TV systems, told investors Tuesday that the company would outline in detail next month its 2005 plans for rolling out Internet protocol telephone services, or VoIP, to its customers.

Following the explosive growth of high-speed Internet access, Comcast and other cable operators see VoIP telephony as one of their key drivers for growth over the next few years.

Cable operators' venture into the telephony business spotlights the continuing turf wars between the cable industry and regional Bell operating companies. Just as cable operators are seeking to take a bite out of telcos' market for voice, telcos such as

Verizon

(VZ) - Get Report

are announcing plans to offer multichannel video services at the foundation of cablers' business.

But while Comcast says it will be ready to offer VoIP to 50% of its customers by the end of 2005, and to 100% by the end of 2006, Alchin and other cable industry executives argued Tuesday that telcos face much higher incremental capital expenditures -- and a much smaller economic payoff -- with their foray into video.

In a presentation at Credit Suisse First Boston Media and Telecom Week in New York, Alchin and Comcast Chief Technical Officer Dave Fellows devoted much of their time to discussing the technology behind, capabilities of and economics of the company's broadband network.

(Comcast announced Tuesday morning that it had entered into a 20-year agreement to obtain 19,000 route miles of fiber backbone from

Level 3

(LVLT)

to augment Comcast's nationwide backbone.)

With Comcast having built out its fiber network, Alchin forecast that the company's 2005 capital expenditures will fall below its estimated 2004 capex of $3.4 billion. Alchin said a $600 million to $700 million reduction in capex devoted to rebuilding the network next year would be offset somewhat by variable spending.

With the decline in capex, free cash flow is expected to grow at twice the rate of operating cash flow over the next two or three years, Alchin said.

Alchin declined to discuss how much it would cost Comcast to upgrade the systems of

Adelphia Communications

, should Comcast end up buying all or part of the bankrupt cable operator in its ongoing auction. But he said that any necessary capex would be factored into the price Comcast is willing to pay.

Fellows said that in building out the national fiber backbone -- covering 95% of Comcast's national footprint -- he made sure to make provisions to connect to Comcast's system in Tupelo, Miss. That was Comcast's first system, back when Comcast's predecessor company was co-founded in 1963 by Ralph Roberts, father of CEO Brian Roberts.

Alchin declined to discuss the incremental cost of adding Tupelo to the national network.