50 years ago: The network of networks is presented to the professional world

As we all know, the Internet has many birthdays. May 19 was one of them, at least for the Institute of Electrical and Electronics Engineers (IEEE). In May 1974, the article "A Protocol For Packet Network Intercommunication" by Vinton Cerf and Robert Kahn appeared in the association's journal "IEEE Transactions on Communication". The idea of a Transmission Control Protocol (TCP), which is suitable for creating a network of networks from several packet-switching networks, was presented to the professional world for the first time. It was to replace the Network Core Protocol of the Arpanet.

There were several events to mark the 50th anniversary, because in addition to the special IEEE birthday, the IEEE also honored the Xerox Alto Computer, the Ethernet and the laser printer. The final event was held at the Computer History Museum. To kick things off, three IEEE Milestone plaques were placed at the Stanford Research Institute 's PARC Forum. They are intended to commemorate the outstanding inventions that were made at the Palo Alto Research Center (PARC), which was maintained by Xerox at the time.

One plaque commemorates the Xerox Alto as the forefather of personal computers, with which the myth of the great user interface heist is associated. Another plaque celebrates the laser printer also developed at PARC with the nerdy name EARS (Ethernet-Alto Research Character Generator Scanning Laser Output Terminal) and a third plaque celebrates the Ethernet developed at PARC and the IEEE standard 802.3. Ethernet inventor Bob Metcalfe received the Turing Award in 2023 and was present at this streamable hybrid event together with Vint Cerf.

Arpanet, ALOHAnet and TCP

The extremely active and well-connected Metcalfe was also the person who, according to Vint Cerf's recollections, introduced Cerf to the editors of the IEEE at the end of 1973 after a computer conference in Brighton, UK. Metcalfe showed the participants how the Arpanet worked and explained its Ethernet and its roots in ALOHAnet, which Norman Abramson had developed. Cerf gave a first insight into the ideas of Robert Kahn and himself. These were ultimately to lead to TCP and Cerf's explanations make it easy to see how and why the outdated NCP protocol of the Arpanet was replaced.

After the conference, he and his partner Robert Kahn worked feverishly on the article (PDF) intended for the IEEE, which hit the professional world like a bomb. For this reason, the IEE, together with Cerf and Kahn, celebrated the publication of the article last weekend.

At the time of publication, TCP was far from being a fully defined protocol. Cerf, a computer scientist who teaches at the University of California, left it to his students to work out the details of the protocol. "I had to go away for two weeks and, after the rough sketch, I asked Yogen Dalal and Carl Sunshine to describe the details," Cerf recounted the development in the book "Soul of the Internet". Accordingly, the names of the two PhD students can also be found in RFC document 675, with which TCP was announced on the Arpanet in December 1974.

From today's perspective, however, the list must be extended to include Gérard Le Lann and Hubert Zimmermann. The two Frenchmen were summer guests at the University of California in 1974. At home, they worked on the Cyclades project, which their professor Louis Pouzin had initiated. Traces of this collaboration can be found in the footnotes to RFC 675. Pouzin had previously been part of a French delegation that was introduced to the Arpanet and developed the French version of a packet-switched data network with Cyclades and the "datagrams" called Cigales. In April 1974, Vint Cerf and Bob Kahn visited Pouzin's institute in France. Back in California, they began detailed work on TCP.

"I have a very vivid memory of Bob Metcalfe, Le Lann and I drawing huge diagrams of how the system should work on the floor of my house in Palo Alto." They can be found as ASCII artwork in the aforementioned RFC 675, the first document to mention the Internet.

Transmission Control Protocol/Internet Protocol

This request document was just the beginning of the technical development of the Internet Transmission Control Protocol. "In the spring of 1976, we began to split the protocol into two halves. I moved from the university to ARPA and worked there under the direction of Bob Kahn," Cerf later recalled the development of TCP/IP, which is documented with its many "Requests for Comment" in RFC 9293. This part of the extensive Internet history also included tests such as that of the "bread truck", which sent the first TCP packet on a transcontinental Internet round trip in 1976. After many test runs, the big changeover did not take place until January 1983.

Vint Cerf and Bob Kahn were also present at the online commemoration of the 50th anniversary of the IEEE article on TCP. Computer scientist Judy Estrin, who put TCP through its paces as a doctoral student under Cerf, was also present. Her father, Jerry Estrin, was the professor who brought Vint Cerf to the University of California as an assistant and supervised his dissertation. Jerry Estrin's wife , computer scientist Thelma Estrin, was the first vice president of the IEEE.

The celebration continued on Monday with a stream from the Computer History Museum, albeit under slightly different auspices. It discussed how the IEEE 802 standardization committee (PDF) came about after Cerf and Kahn's TCP proposal and what the plaques for the Xerox Alto, Ethernet and laser printer are all about.

Another Milestone badge was also awarded. It went to Google's Page Rank, the algorithm that led to the creation of Google between 1996 and 1998. In keeping with the non-material nature of the algorithm, there is only one virtual commemorative plaque. It could be accepted by 80-year-old Vint Cerf, who has been employed by Google as "Chief Internet Evangelist" since 2001. There he is working on the interplanetary Internet as the next development stage of TCP.

(dz)