Broadband Integrated Services Digital Network (B-ISDN) is conceived as an all-purpose digital network supporting interactive and distributive services, bursty and continuous traffic, connection-oriented and connectionless services, all in the same network. The concepts of ISDN in general and B-ISDN in particular have been evolving since CCIIT adopted the rrrst set ofISDN recommendations in 1984. Thirteen recommendations outlining the fundamental principles and initial specifications for B-ISDN were approved in 1990, with Asynchronous Transfer Mode (ATM) being the transfer mode of choice for B-ISDN. It seems fair to say that B-ISDN concepts have changed the face of networking. The expertise we have developed for a century on telephone systems and over a number of decades on packet networks is proving to be insufficient to deploy and operate the envisioned B-ISDNs. Much more needs to be understood and satisfactorily addressed before ATM networks can become a reality. Tricomm'93 is dedicated to A TM networks. The technical program consists of invited papers addressing a large subset of issues of practical importance in the deployment of ATM networks. This is the sixth in a series of Research Triangle Conferences on Computer Communications, which emerged through the efforts of the local chapter of IEEE Communications Society.