We consider queueing networks with sub-exponential service times distributions (STD).
1. For a class of stable monotone separable queueing networks, we get upper a low bounds for the tail distribution of a stationary maximal dater. Then we obtain a sharp asymptotic for particular models (including tandem queues, generalized Jackson networks). Finally, a sharp asymptotic for a stationary waiting time in generalized Jackson networks is obtained, too.
2. For a stable () 2-server queue with FCFS policy, a sharp
asymptotic for
a stationary waiting time distribution is obtained when either
(i) and a second tail of STD is sub-exponential, or
(ii) and STD is regularly varying.