“…For studies on other characteristics (the queue size, loss probability, response time) of systems with the dropping function, or carried out under different assumptions on the arrival process and service times, we refer the reader to [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. On the other hand, there are several papers on the time to reach a given level in classic queueing models, i.e., without the dropping function—see, for example, [ 29 , 30 , 31 , 32 , 33 ] and the references given there.…”