Merit Celebrates 20th Anniversary
There is considerable merit in NSFNET
By John Mulcahy
This year marks the 20th anniversary of Michigan's Merit Computer Network, managers of the NSFNET backbone. Merit connects the state from its industrial southeast to the shores of Lake Superior, providing over 11,000 computer communication ports to scholars, researchers, and citizens. It counts eight of Michigan's state-supported universities as host- supporting members, and provides access to thousands of host computers and other networks around the world. From its initial development in 1969, Merit has grown to become an important state and national resource for computer communications.
The most obvious symbol of Merit's current importance to the nation is its management of the National Science Foundation's backbone network, NSFNET. Already, many people see it as a model for an even larger national network, linking every higher education and research facility in the country.
Merit President, Eric Aupperle, is particularly proud of the way Merit has worked with its private sector partners on the NSFNET project. "This demonstrates that it can be done, which runs contrary to the prevailing thinking," says Aupperle, who joined Merit as a project leader in 1969 and served as associate director and director before becoming president in 1988.
Joining diverse organizations and technologies has always been Merit's strong point. When network design began in 1969, according to Aupperle, the planners looked for ready made data communications equipment to link the different computing systems at Merit's three original member universities: Michigan State University, Wayne State University, and the University of Michigan. It soon became apparent that no readily available commercial equipment would do the job.
Merit solved the problem by designing interfaces for the Digital PDP-11 computer for its main communications device. The new network then hired Applied Dynamics Division of Reliance Electric to manufacture the new components, and one of the customized PDP-11 systems was installed at each of the three universities. These machines' descendants still make up the backbone of the Merit statewide network.
Merit personnel write own software
Just as important to Merit as finding the right hardware was writing its own software, or operating system, to run in the network's computers, and writing its own networking protocols, which it called INP (Inter-Nodal Protocol).
"There was very much a pioneering effort in software development around this place," says Merit Associate Director Scott Gerstenberger. Gerstenberger, who began working for Merit in 1988, was with the U-M Computing Center in the early days of Merit and acted as a liaison between the two organizations. He was instrumental in developing the Center's data concentrators, features of which were incorporated into the Merit backbone PDP-11 machines.
"You had to roll your own," Gerstenberger says of the early days of network development. The challenge today is in making choices among the many networking technologies, he explains. "Nowadays, the world's into networking in a big way."
Appeal to the Legislature
Merit can trace its roots before 1969 to some blue-ribbon committee recommendations made for Michigan Governor George Romney in 1963. In response to those recommendations, then University of Michigan Vice President Roger Heyns got the idea for a state-wide learning center. At Heyn's request, psychology professor Stanford Ericksen, then director of the University of Michigan's Center for Research on Learning and Teaching, and Ericksen's staff member, Karl Zinn, came up with a proposal for the University's 1964 legislative budget request, including the network idea.
Both Ericksen, now retired, and Zinn, still a research scientist at the U of M Computing Center, stress that the original plan had more to do with education than computer networks. However, the network proposal was the only one that caught the state legislature's eye.
"The computer network idea took on a great deal of fervor," said Ericksen of the original proposal. In response to legislative enthusiasm, Ericksen and Zinn helped form a committee with representatives from all the state-supported schools to study the idea. It took two years to get a serious effort under way, according to Zinn.
By that time, only Michigan's three biggest schools were still actively pursuing the network idea. These universities formed the Michigan Inter university Committee on Information Systems (MICIS). At MICIS' recommendation, the officers of the three universities formed MERIT, Inc., as a non-profit corporation in 1966.
Merit spent three years finding funds to begin development, first getting $400,000 from the state legislature provided it could find matching funds somewhere else. Merit appealed to the National Science Foundation, and after two proposals and some lengthy negotiations got a matching grant in July 1969, according to Zinn, who helped write the proposals.
Looking back at the days before and after the initial trial, Merit's first director, Bertram Herzog, recalls that the challenges were institutional as well as technical. "Those early days were kind of rough to get through," Herzog says. "There was a strain on all our sensibilities to get this thing working in a non-technical way." Herzog, who was hired in 1968, remained director until Aupperle took over that position in 1974 .
Most challenging was fostering cooperation among the three schools, according to Herzog. "They had never had the need to cooperate in that depth," he says. "I think we all felt good that we got it done."
Merit's trial run came in December 1971, a successful connection from the University of Michigan to Wayne State, followed by a University of Michigan to Michigan State connection in October 1972, and a formal dedication ceremony in May 1973.
In the beginning, Merit was a "host-to-host" network. That meant the user signed on to a local host and used it to access a remote host. The next big step was the development of dial-in access and direct terminal support by the network so that the network controlled the behavior of the user's terminal. This meant the user accessed the network itself, and could connect to a remote host even if the local host wasn't working. Work started on this in 1975, just about the time the current head of technical support, Christine Wendt, came to Merit as a user consultant.
"This really signalled the beginning of the change," Wendt says. "Suddenly they (people who reached Merit) were users of the network proper, and the network was the main thing."
The effort to build user interest and access was an important part of the early Merit strategy, according to its president.
"It became quite apparent that traffic wasn't going to just happen unless there were some efforts to educate the user community about this," Eric Aupperle says. To this end, Merit began providing user support services. One Merit innovation in this area was the use of computer conferencing for consulting.
"We were absolutely the first to use it for this," says technical support leader Wendt.
Another idea to make life easier for the user was exchange accounts. By this mechanism, still in use at Merit, a user who wants to access a remote host can obtain an exchange account with the local host and pay at rates set by it. The mechanism reflects both the adaptability of Merit and the autonomy of its member institutions.
Besides changing its relationship to its users, Merit had also changed its relationship to its members. After a final $200,000 appropriation in 1972, the state legislature ended direct Merit support, and the network began charging membership fees. Beginning in 1974, each member paid $55,000 a year. The move to membership fees was fortunate, according to president Aupperle, because it demanded a new level of commitment by the member universities.
"When you pay for something, you have to make a value judgment," Aupperle says.
More Outside Links
Merit now began to relate to the outside world in other ways. In1976 it opened its first connection--two slow, asynchronous lines--with the commercial network Telenet. Though in part an experiment to see if Merit would get any Telenet calls, the step meant Merit users could now connect with a local telephone call in any of the localities served by Telenet in the U.S. and overseas.
Over the next four years, demand for Telenet access into Merit caused Merit to install first a small, then a larger, Telenet-built interface box. By 1980, Telenet had begun to support the new, international standard X.25 protocol, and Merit followed that year by writing its own X.25 implementation.
This standard, circuit oriented protocol not only gave Merit a much more sophisticated connection to Telenet, but freed Merit from the necessity of developing a custom-tailored interface for each vendor whose host or network equipment it attached. Through it all, Merit retained its commitment to its own internal protocol, once again demonstrating its native talent for adaptability.
Support for TCP/IP
The latest crucial step for Merit came when it began to develop its ability to handle Internet Protocol (IP) traffic. TCP/IP, developed by the ARPA network, had by this time become a major component of the national academic computing infrastructure. Merit was uncharacteristically slow to adopt IP, due in part to the strong computing environments at the three original universities.
"Given the excellence of the mainframe systems here among our initial three members, there really wasn't the requirement for Merit to have IP connectivity," Aupperle says. "Our environment didn't really press us into that initiative until relatively late in the game." Merit started developing its IP abilities in about 1986, he adds.
Among others, Aupperle credits Hans-Werner Braun with pushing this development. Braun, who came to Merit in 1983, is principal investigator for the NSFNET backbone project, and head of Merit's Internet Engineering group.
"When I first came to Merit, I had never even heard of IP," notes Braun. A serendipitous encounter with the IP gateway software of Dave Mills, who had years before played a major role in developing the University of Michigan's first data concentrator, prompted Braun to get in touch with Mills, then working under contract to ARPA. Braun readily credits Mills with tremendous help in getting Merit started down the IP path.
"The whole thing really started out as a spare time project," Braun reminisces.
Along with Allan Rubens, much of the work on Merit's IP implementation was done by Mark Knopper, who came to Merit in 1980. Knopper points out that while Merit was then and still is committed to working with international standards bodies, the IP protocol suite is "standardized" only through the circulation of documents called Requests For Comment (RFCs).
"The real goal of our IP implementation," says Knopper, "is that it positions us for implementation of the International Standards Organization's OSI protocols." Developing a plan for migration to the OSI protocols is, in fact, an important requirement in Merit's agreement to manage NSFNET.
Besides growing technically and in connectivity, the Merit family had also grown,
beginning in 1979 with the addition of Western Michigan University. By 1987, eight
of the state-supported universities in Michigan were members. In 1988, the Merit
Board opened membership to any 4-year university or college in Michigan.
Perspective on the Network
As he looks back on the growth of Merit, Aupperle says the only thing he regrets is that the process was not accelerated. He attributes what he sees as the slow tide of network growth to a lack of awareness about what a network can do. He especially sees computer conferencing and electronic mail as initiatives that got more people involved. Philosophically, he adds that networking is an evolutionary process, with each new step adding to people's awareness.
Looking to the future, Aupperle sees great opportunities and some important questions for the network. He foresees a time when junior colleges and private institutions in Michigan may be members. He speculates whether Merit could become the center of the frequently envisioned national network linking all research centers and institutions of higher education in the country, and notes that Merit is recognized as a major national networking resource.
One hurdle he sees is the move to commercialize networking at the national level. In its current form, as a unit of higher education, Merit may not be properly structured for this move, he says. How Merit moves to meet this challenge is one of the most important issues facing its Board of Directors, made of up representatives of all the member universities.
Editor's Note: A version of this article first appeared in the Summer-Fall 1989 edition of Harvard University Information Technology Quarterly, Vol. VIII, Nos. 2 and 3.
Taken from The Link Letter, December 1989, Vol. 2 No. 6.