Congestion judging method and switch in lossless network

Abstract

The invention provides a congestion judgment method in a loss-free network. The method comprises the following steps of pausing sending of a data packet when a PAUSE frame of a next-hop device arrives; when a RESUME frame of the next-hop device arrives, recording the number of the data packets in a current sending queue as the reference number, and recovering the sending of the data packet; and after the number of the sent data packets exceeds the reference number, acquiring a first congestion detection index when each data packet is sent continuously, and if the first congestion detection index exceeds a first preset threshold, carrying out congestion marking on the sent data packet. According to the embodiments of the invention, the defects that the accuracy is low and the flow independent of the congestion is easily influenced due to the fact that whether a congestion mark is added to the data packet is judged only according to the length of the queue are overcome, the defects thatPFC is easy to generate a congestion tree and is rapidly expanded are overcome, the method has an advantage of being more accurate in adding the congestion mark, and a foundation is provided for further judgment and congestion processing of the congestion flow.

Description

technical field [0001] The invention relates to the technical field of network congestion control, in particular to a congestion judging method and a switch in a lossless network. Background technique [0002] In order to realize the lossless feature in the data center Ethernet, many network devices currently support the priority-based flow control mechanism PFC (priority-based flow control). PFC divides the traffic into 8 priority levels and monitors the accumulation of each priority traffic on the ingress port of the switch. When a certain priority traffic exceeds the given threshold X_OFF, the switch sends a PAUSE frame to the next hop to terminate the transmission of the priority traffic; when the accumulation of the priority traffic in the queue is lower than another given threshold X_ON, the switch then Send a RESUME frame to resume transmission. However, PFC will cause the congestion tree to be generated and expanded rapidly, causing head-of-line blocking and reduci...

AI Technical Summary

Problems solved by technology

In this process, although the congestion control mechanism eventually restores the congestion-independent flow to its reasonable throughput, it still causes a loss of throughput for a period of time.

In scenarios with high concurrency and high burst short flows (such as data centers, cluster systems, etc.), frequent instantaneous congestion will be caused and the PFC mechanism will be triggered, resulting in frequent deceleration of congestion-independent flows, and the throughput loss in a short period of time will eventually accumulate Cause severe network performance loss

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