For instance, in the early 1990s, little research money was put into router technology, with the result that until recently, routers lagged behind other technologies. The result was that people didn't buy new higher-speed transmission technologies because they didn't have routers to plug them together. Expressed another way, one cannot just fund leading research in one field, because those results won't be usable until the other fields catch up. We need to assess the state of each field and balance the research agenda to ensure that no field gets left too far behind. Second, like most fields, networking research has its fads or popular technologies.
Fads often get more attention than they deserve.
ATM has proved disappointing. Non-ATM technologies were neglected. Third, research results take time. The work requires hard thought and much research depends on the availability of recent PhDs and PhD students. Research funding started in 1997 may not pay off until 2001 when the relevant Ph.D. candidate finishes her thesis.