Output characterization of constant bit rate traffic in FIFO networks

We provide an analytical proof that the departure rate of a CBR flow at an overloaded link with FIFO buffers is proportional to the flow´s share of the total offered load at the link. This property of FIFO scheduling was recently validated in in a series of traffic measurement experiments. An extension of the analysis to a multi-node scenario shows that the output rate of a flow in a network with many overloaded FIFO switches approaches the pessimistic values given by blind multiplexing.