A Flow Control Scheme Based on Per Hop and Per Flow in Commodity Switches for Lossless Networks

Shie-Yuan Wang,Ruei-Syun Lai,Hsien-Chueh Hsieh,Yo-Ru Chen,Yi-Bing Lin

doi:10.1109/access.2021.3129595

Shie-Yuan Wang, Ruei-Syun Lai + Show 3 more

Open Access

https://doi.org/10.1109/access.2021.3129595

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Journal: IEEE Access	Publication Date: Jan 1, 2021
Citations: 3	License type: CC BY 4.0

Affiliation: National Yang Ming Chiao Tung University

Abstract

Performing flow control inside a network can effectively avoid packet loss due to buffer overflow in switches. IEEE 802.3x exercises a per-hop link-based flow control scheme to achieve this goal. IEEE 802.1Qbb Priority-based Flow Control (PFC) improves IEEE 802.3x by proposing a per-hop per-service-class flow control scheme. Although PFC is better than IEEE 802.3x, it still suffers from several serious problems such as congestion spreading, deadlock, and packet loss. In this work, we propose a per-hop per-flow scheme to mitigate these problems. We design, implement, and evaluate the performance of our scheme in P4 hardware switches. Experimental results show that (1) our scheme outperforms PFC in many aspects including avoiding congestion spreading, deadlock, and packet loss, and (2) the bandwidth overhead of our scheme is only slightly higher than that of PFC.

Highlights

P ACKET losses due to buffer overflow in network switches may occur due to network congestion
If the UDP protocol is used at the transport layer, a UDP sending host will not automatically retransmit lost packets, which may result in poor Quality-of-Service (QoS) of the network applications on the receiving host
We evaluate the real-world performance of perflow flow control scheme (PFFC) on a multihop network testbed composed of several P4 switches and hosts

Summary

Introduction

P ACKET losses due to buffer overflow in network switches may occur due to network congestion. To prevent dropped packets due to buffer overflow in network switches, IEEE 802.3x [1] proposed a per-hop linkbased flow control scheme to ensure zero packet loss between two adjacent network nodes. Because IEEE 802.3x is linkbased, when a link is stopped, all flows on the link are stopped, including those flows that are not congested in the downstream node. When a link is stopped due to a high buffer usage of low-priority flows, flows of high priorities are stopped as well. Later on, when the buffer usage drops below another threshold Xon, NR will send a RESUME frame to NS to resume transmission of packets on the link. To ensure that no packets are dropped in a network due to buffer overflow in any switch, IEEE 802.3x is exercised on every link.

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