Before revision:  We therefore provide an upper bound of the average Age of Information in a parallel server system of an arbitrary number of M/M/1/(N+1) queues and  its tightness in various regimes.
After revision:  We therefore provide an upper bound of the average Age of Information in a parallel server system of an arbitrary number of M/M/1/(N+1) queues and show its tightness in various regimes.