DeepQoS: Core-Stateless Hierarchical QoS in Programmable Switches

Abstract

Novel applications and network scenarios challenge existing traffic management strategies. Hierarchical Quality of Service (HQoS) provides a fine control of resource sharing and delay, but traditional HQoS solutions have challenging complexity that prevents their deployment in the traffic management engine of high-speed switches. Programmable switches have emerged to make the packet processing pipelines flexible and reconfigurable, but their traffic management capabilities still rely on fixed functions that cannot handle the complexity of traditional HQoS approaches. In this paper, we show how the extended programmability can help in addressing this challenge by the application of a fundamentally different algorithm. To emulate HQoS behavior we extend our core-stateless resource sharing framework called Per Packet Value (PPV) with a HQoS-packet marker architecture called DeepQoS. DeepQoS can be used to mark resource sharing policies of different layers simultaneously and effectively at a single point, e.g., ensuring the fair share of a household’s traffic within an access aggregation network, while also controlling the shares of its subflows. In the PPV framework, bottleneck scheduling is very simple and is unaware of flows and policies, which are encoded to Packet Values. DeepQoS can use these existing simple PPV schedulers without any change. To demonstrate the deployability of the proposed method, we have created the DeepQoS marker implementation in DPDK while redesigned and implemented our packet scheduler called Virtual Dual Queue Core Stateless Active Queue Management (VDQ-CSAQM) on a P4-programmable switch. Using extensive measurements we demonstrate the unique capabilities of DeepQoS to realize rich and deep HQoS.