Current and advanced protocols over ATM: evaluation, implementation and experiences

This paper describes recent experiences with evaluating and implementing advanced communication protocols on top of ATM. First, experiences and performance results with conventional TCP/IP over ATM based on Digital Equipment's Gigaswitch/ATM are reported. Moreover, the behaviour and performance of application-level remote procedure call protocols with mass data transfer extensions over ATM is discussed. It becomes obvious that current protocols must be tuned specifically in order to exploit ATM performance. Moreover, the lack of reservation facilities, especially in heterogeneous environments, has been identified as another significant problem; currently, no quality of service guarantees are possible. In order to address the quality of service issues, the second part of the paper describes advanced concepts and an implementation of IPng (IP next generation) and RSVP (Resource Reservation Protocol) over ATM. Particular emphasis is put on the problem of mapping quality of service and traffic parameters in an adequate way. Moreover, the issue of address mapping from IPng onto ATM is also discussed. First implementation results in these areas are presented. The paper finally concludes with an outlook to future work in the area of resource reservation in advance.