Abstract—Recent studies showing that the output of traffic flows at packet switches has similar characteristics as the corresponding input enables a decomposition analysis of a network where nodes can be studied in isolation, thus simplifying an endto-end analysis of networks. However, network decomposition results available today are mostly many-sources asymptotics. In this paper we explore the viability of network decomposition in a non-asymptotic regime with a finite number of flows. For traffic with Exponentially Bounded Burstiness (EBB) we derive statistical bounds for the output traffic at a FIFO buffer and compare them with bounds on the input. Evaluating the accuracy of the output bounds with exact results available for special cases and by numerical illustrations we find that conditions for network decomposition appear favorable even if the number of flows is relatively small. I.

In this paper we consider the case of a FIFO multiplexer fed by flows that are individually constrained by piecewise linear concave arrival curves. We show that, contrary to what happens at the input, at the output not all valid scenarios in accordance with the worst case arrival curves can occur. This implies that taking an iterative approach to characterize the arrival curves at the output when flows pass throughout several FIFO nodes is suboptimal (in the sense that, although valid, they do not necessarily have to be the best arrival curves that can be found).