  Deterministic IP (DIP) networking is a promising technique that can provide
delay-bounded transmission in large-scale networks. Nevertheless, DIP faces
several challenges in the mixed traffic scenarios, including (i) the capability
of ultra-low latency communications, (ii) the simultaneous satisfaction of
diverse QoS requirements, and (iii) the network efficiency. The problems are
more formidable in the dynamic surroundings without prior knowledge of traffic
demands. To address the above-mentioned issues, this paper designs a flexible
DIP (FDIP) network. In the proposed network, we classify the queues at the
output port into multiple groups. Each group operates with different cycle
lengths. FDIP can assign the time-sensitive flows with different groups, hence
delivering diverse QoS requirements, simultaneously. The ultra-low latency
communication can be achieved by specific groups with short cycle lengths.
Moreover, the flexible scheduling with diverse cycle lengths improves resource
utilization, hence increasing the throughput (i.e., the number of acceptable
time-sensitive flows). We formulate a throughput maximization problem that
jointly considers the admission control, transmission path selection, and cycle
length assignment. A branch and bound (BnB)-based heuristic is developed.
Simulation results show that the proposed FDIP significantly outperforms the
standard DIP in terms of both the throughput and the latency guarantees.
