Betting that video will drive the future of networking, Cisco Systems Inc. agreed Friday to buy the cable television technology company Scientific-Atlanta Inc. in a $6.9 billion deal that would create a one-stop shop for sending TV over the Internet.

The acquisition is expected to help fuel the revolution in how TV is distributed and watched – a change that’s accelerating as telephone companies barge into the domain of cable operators and begin offering programming over fiber-optic networks using the language of the Internet.

It also fits Cisco’s strategy of moving into areas that are converging on the Internet Protocol standard – a shift that creates an opportunity to increase revenue with new business and enhance its traditional routers and switches that direct data over networks.

For providers and consumers, Internet-based television promises expanded choices, lower costs and new services in the same way voice over the Internet Protocol has made phone calls less expensive and enabled features that were not possible with the traditional telephone network.