On the Jitter Performance of FIFO and Priority Queues Mixture

We investigate the impact of the insertion of routers implementing a non-preemptive priority queue mechanism (PQ) in a chain of simple first-in-first-out (FIFO) routers on the end-to-end jitter experienced by high and low priority packets. The study has been realized from an analytical point of view: we are able to give the explicit form of the total jitter in relation to the time that a packet spends in queue. We study its behavior as a function of the input rate of the high and low priority packets and of the number of PQ routers present in the whole path by showing an evident decrease of the high priority packets jitter with respect of the case of a chain composed by only FIFO nodes