\section{Conclusions and Future Work}

We measured the traffic characteristics of six parallel programs on
an Ethernet.  The conclusion to be drawn from the measurements is that
the traffic of parallel programs is fundamentally different from the
media traffic that is the current focus of QoS research.  Unlike media
traffic, there is no intrinsic periodicity due to a frame rate.  Instead,
the periodicity is determined by application parameters and the network
itself.  We suggested a traffic characterization and service negotiation
model that allows the network to modulate application parameters in
an effort to achieve the best performance possible given the current
network state.  This is clearly an important area for future research.