Cisco (CSCO) can't seem to help itself. Each year it buys several companies, some of them big. Early today the router company agreed to buy Oslo-based Tandberg. The deal will close early next year and under the terms of the transaction Cisco, which has about $35 billion in cash and short-term investments on its balance sheet, will pay about $3 billion in cash for the company.

Tandberg makes video infrastructure and communications products which gets Cisco much more deeply into that sector. Cisco already owns Linksys and TV set-top company Scientific Atlanta. Its TelePresence unit is a force in video conferencing, and it has bought a number of other small businesses in related areas.

Several years ago, John Chambers, Cisco's long-time CEO, realized that video communications and the transport of video files and live video images over the internet would be big business, and planned to make it a large part of Cisco's operations. Cisco's legacy router operations already power many key data hubs that move information over IP, and Chambers sees video products as a natural extension of that business.

Wall Street has been consistently impressed by Cisco's ability to integrate new companies with very little disruption. The company has a market cap of $136 billion, making it one of the 15 most valuable companies in America, ahead of other tech giants including Intel (INTC) and Oracle (ORCL).

Wall Street will likely have a positive reaction to this new purchase. Chambers has done well with his strategy to expand Cisco and rarely makes big mistakes..

Douglas A. McIntyre is an editor at 24/7 Wall St.