The top network inventors of all time

A look back at the network industry's greatest inventors

Although boxing legend George Foreman, a judge on the second-year CBS reality show American Inventor, has yet to invent a network device, his Lean Mean Grilling Fat-Reducing Machine has been used by countless techies to quickly cook sandwiches and hamburgers after a long day in the data center.

The show on which Foreman appears also inspired us to take a look back at the network industry's greatest inventors. And who knows, maybe the winner of American Inventor will someday join our list.

Inventors: Herman Andrew Affel and Lloyd Espenschied

Invention: Coaxial cable -- 1929

The story: Affel and Espenschied invented what they called the Concentric Conduction System at AT&T Bell Laboratories in 1929. (OK, we could have included Alexander Graham Bell on our list, but didn't want it to be too predictable). Coaxial makes it possible to carry thousands of phone calls on long-distance circuits. It was first commercially used in 1940 and a year later, AT&T used it to establish a transmission system between Minneapolis and Steven's Point, Wisconsin, that could carry 480 telephone conversations and one television program. Coaxial gave way in 1983 to fiber-optic cabling. Coaxial cable also helped LANs get off the ground

Inventors: Paul Baran and Donald Davies

Invention: Digital packet switching -- 1950s

The story: Baran, the brains behind digital packet switching, came up with a replacement for circuit-switched networks with his Packetized Ensemble Modem. Baran's work at RAND resulted in a distributed mesh network that could reconfigure itself around non-working areas. His work was in response to U.S. concerns about its defense system surviving a first strike from the Soviet Union during the Cold War. In Baran's and Davies' packet switched network, communications were broken into packets that would be rejoined at their destination and nodes were interconnected to many other nodes so that data could be transmitted over alternate paths. In 1964, Baran also came up with the idea of a doorway gun detector, like those used in airports.

Inventor: Robert Metcalfe

Invention: Ethernet -- 1973

The story: Metcalfe invented the Ethernet protocol at Xerox Palo Alto Research Center in 1973. The patent was filed as Multipoint Data Communication System with Collision Detection. A quarter billion Ethernet switch ports now ship annually. Metcalfe, who founded 3Com on the heels of his invention, has gone on to fund other companies as a general partner at Polaris Venture Partners.

Inventors: Vint Cerf and Robert Kahn

Invention: TCP/IP -- 1974

The story: Cerf and Kahn designed the Internet architecture and the protocols that let computers access and use it. Known as Transmission Control Protocol/Internet Protocol (TCP/IP), the suite of protocols became the standard way to interconnect and use the Defense Advanced Research Project Agency and today's modern networks. Cerf is now vice president and chief Internet evangelist at Google. Kahn is chairman of the Corporation for National Research Initiatives, a nonprofit company involved in the development of the National Information Infrastructure.

Inventors: William Yeager and Andy Bechtolsheim

Invention: Multi-protocol router software and hardware --1980-1981

The story: Yeager, an engineer at Stanford University, was charged with linking the engineering and computer science networks across the campus. He developed the EtherTIP routing code. Yeager claims he permitted Len Bosack, the director of Stanford's Computer Science Department, to use the source code. Unbeknownst to Yeager, Bosak and Sandy Lerner incorporated Cisco Systems and used the router source code as the basis of the first Cisco IOS. Bechtolsheim, a Stanford Computer Science Department student, came up with the router hardware. He went on to co-found Sun, where he is chief scientist.

Inventors: Mark Dean and Dennis Moeller

Invention: Computer peripheral bus -- 1984

The story: Dean and Moeller created the PC Bus for attaching peripheral devices such as disk drives and printers to the personal computer. Technology genes unveiled themselves early for Dean, who built a tractor from scratch as a child; at IBM, Dean is a Fellow. Moeller also is with IBM. Without their technology, iTunes would have to be dowloaded to an iPod through a telephone connection.

Page Break

Inventor: Jon Postel

Invention: Simple Mail Transfer Protocol (1982), File Transfer Protocol (1985) and User Datagram Protocol (1980)

The story: Protocol guru Postel, who died in 1998 at the age of 55, is known for his work in the early Internet. He invented the SMTP, a de facto standard for sending mail across the Internet; FTP, which like SMTP, is a protocol for exchanging information -- in this case, files -- over the Internet; and the UDP, which is part of TCP/IP and lets computers send short messages to each other. Ira Magaziner, who served as former President Bill Clinton's Internet policy advisor, recalled in a University of Southern California publication that the wooly bearded, often eccentrically attired Postel was once detained by Secret Service agents for 20 minutes prior to a meeting at the White House before they realized he really did have business there.

Inventor: Radia Perlman

Invention: Spanning-tree algorithm -- 1983

The story: The spanning-tree algorithm, used by all bridges and switches to route traffic from one point to another, is credited to Perlman, then working at Digital Equipment. Now sometimes called the Mother of the Internet, Perlman is a distinguished engineer at Sun, where her goal is killing off the technology she invented. The algorithm is too fragile, she says -- if a temporary loop was created, it could cause problems from which the network might never recover. "It's time to redo it in a way that is more robust and gives more efficient paths," Perlman says in her bio on Sun's site.

A poem written by Perlman describes the Spanning Tree Algorithm:

I think that I shall never seeA graph more lowly than a treeA tree whose crucial propertyIs loop-free connectivity. A tree which must be sure to spanSo packets can reach every LAN.

First the Root must be selectedBy ID it is elected.Least cost paths from Root are traced.In the tree these paths are placedA mesh is made by folks like meThen bridges find a spanning tree.

Inventors: Marshall Rose, Jeff Case, Keith McCloghrie and Steve Waldbusser

Invention: The Simple Network Management Protocol -- 1987

The story: Rose, Case, McCloghrie and Waldbusser cooked up SNMP as a way to manage distributed devices on a network. SNMP is simple in design -- it has only five commands for managing information: Get_Request, Get_Next_Request, Set_Request, Get_Response and Trap. It's no surprise so many vendors adopted it for their devices.

Inventor: Charles Hedrick

Invention: Routing Information Protocol - 1988

The story: Hedrick is responsible for RIP, a protocol that lets routers determine which networks they can communicate with and how far away those networks are. ARPANET used RIP as its initial routing algorithm.