In this period, he also worked several years in the labs of Bellcore in Red Bank, New Jersey (USA), working in the TINA-C Core Team, and helping to produce architectural models for telecommunication services.
He then joined Bell Communications Research (Bellcore), a separate corporation from the Bell Labs (now Telcordia Technologies), as a research scientist.
After successful experiments with Voice over Ethernet from 1981 to 1984, Dr. W. David Sincoskie joined Bellcore and began addressing the problem of scaling up Ethernet networks.