From the corporate boardroom to the enterprise data center, the 50 men and women on this list exercise power within the network industry to one degree or another. Some have the clout to sway the world's technology decisions, while others command attention within vertical industries, particular market segments or simply - though not inconsequentially - within their own organizational domains. We have ranked each of our 2004 power-brokers based on such stature, as well as on the person's visibility and the ways in which the person functions as a role model. To see how these 50 fit together, we've aligned them by category as well, from the titans to the standards-setters.

THE TITANS.

John Chambers, president and CEO, Cisco

If Chambers does nothing more, he commands customer loyalty. This is the fifth straight year, for example, that readers participating in our annual Powerometer survey named Chambers the most powerful man in the network industry (see related story). In 2005, watch for Chambers to battle far more aggressively than he has been against encroaching Chinese competitors, particularly Huawei Technologies.
Rank: 1, Last year's rank: 1

Charlie Giancarlo, senior vice president and CTO, Cisco; president, Cisco-Linksys

Giancarlo's stature increased this year with his rise to the prestigious CTO position, from where he contributes to and communicates Cisco's technology strategy. At the same time, he continues overseeing Cisco's critical voice efforts and home network business. Among the many huge deals Giancarlo orchestrated in 2004 was one in which Verizon selected Cisco-Linksys gear for home network installs.
Rank: 13, Last year's rank: 17

Steve Ballmer, CEO, Microsoft

Ballmer never relents in his hardball tactics against Linux and the open source movement. In a recent speech before government officials in Singapore, for example, he asserted that Linux is loaded with patent-infringing code and that one day all nations petitioning for entry into the economic World Trade Organization will be subject to investigation on the matter. Whew!
Rank: 11, Last year's rank: 12

Dave Dorman, chairman and CEO, AT&T

Does he want to sell AT&T or doesn't he? While the world contemplates that question, Dorman remains king of long-distance services and global data networking. As such, Dorman spent 2004 bolstering AT&T's attractiveness to enterprise network executives (or potential buyers). For example, Dorman oversaw the expansion of AT&T's Multi-protocol Label Switching (MPLS) network globally.
Rank: 12, Last year's rank: 10

Larry Ellison, chairman and CEO,  Oracle

With the drama of the Oracle/PeopleSoft battle ending in victory for Oracle, Ellison's industry power is clearly on the rise. His next challenge will be to quickly integrate PeopleSoft products to avoid a massive customer exodus, including the JD Edwards products Oracle inherited with this $10.3 billion acquisition.
Rank: 14, Last year's rank: 20

Carly Fiorina, chairman and CEO, HP

Highlights of Fiorina's year include several acquisitions aimed at strengthening HP's position in the evolving on-demand world. Among those now calling HP home are software management companies Consera Software and Novadigm. Look for Fiorina to spend 2005 emphasizing her message that HP isn't all about the hardware, but about those very profitable software products, too.
Rank: 4, Last year's rank: 4

Gary Forsee, chairman and CEO, Sprint

No question about it. The Sprint/Nextel merger announced Dec. 15 and expected to close in the second half of 2005 was the surprise move of the season. With Forsee slated to become president and CEO of the new company, his future industry power is assured.
Rank: 17, Not on last year's list.

Bill Gates, chairman and chief software architect, Microsoft

The ultimate IT industry icon, Gates has an open invitation the world over to share his vision. Naturally, he casts Microsoft consumer and enterprise products in starring roles in his version of a sci-fi computer-centric future.
Rank: 2, Last year's rank: 2

Sam Palmisano, chairman and CEO, IBM

As leader of the No. 1 company on the Network World 200, our annual ranking of the top 200 network vendors, Palmisano's influence is vast - and not just in IT. His job gives him access to CEOs at leading companies worldwide. He's been known to chit-chat over leadership skills with the CEO elite crowd, even as he prowls for business.
Rank: 3, Last year's rank: 3

Ivan Seidenberg, chairman and CEO, Verizon

With an aggressive plan for expanding fiber-to-the-premises (FTTP) technology in six new states, Seidenberg aims at turning the Baby Bell into a true competitor to the cable companies, for data and video. While Seidenberg will continue his unrelenting fight against regulatory control in 2005, he'll also push the edge on new enterprise offerings, from managed LAN and VoIP services to 3G.
Rank: 5, Last year's rank: 6

Ed Whitacre, chairman and CEO, SBC

At times overshadowed by Verizon's Seidenberg as the Bell CEO to watch, Whitacre has shown plenty of reasons this year why he deserves our attention. Under his leadership, SBC in 2004 orchestrated a $100 million, 50,000-phone contract to create a managed VoIP network for Ford Motor, rolled out a hosted VPN service nationwide, and committed to invest $6 billion in an FTTP initiative.
Rank: 10, Last year's rank: 11