Before revision:  We highlight that in a high bandwidth-delay product  regime, and with a large number of long-lived flows, the bottleneck queue may be modelled as an M/M/1/B or an M/D/1/B queue.
After revision:  We highlight that in a high bandwidth-delay product and a small buffer regime, and with a large number of long-lived flows, the bottleneck queue may be modelled as an M/M/1/B or an M/D/1/B queue.