Packet Loss Detection System and Method for Packet Transport Network

Abstract

The invention provides a packet loss detection system of a packet transmission network, which includes a threshold relationship setting module, a degradation threshold setting module, a sampling threshold selection module and a packet loss detection module, and the threshold relationship setting module is used to set the degradation and sampling gates as required Corresponding relationship of the limit value, the degradation threshold setting module is used to set the degradation threshold value as required, the sampling threshold selection module is used to select the corresponding sampling threshold value according to the set degradation threshold value and the set relationship, and the packet loss detection module is used to It counts the number of sent packets in a statistical period and judges whether the counted number of sent packets is less than the selected sampling threshold value, and if it is less than the selected sampling threshold, it stores the counted number of sent packets and accumulates them until the next statistical period to calculate the packet loss rate. When sampling the threshold value, the number of sent packets is accumulated to the next statistical period so that the counted number of sent packets in each statistical period is greater than or equal to the sampling threshold value, which improves the accuracy of packet loss rate detection. The invention also provides a detection method.

Description

technical field [0001] The invention relates to packet network transmission technology, in particular to a packet loss detection system and method of a packet transmission network. Background technique [0002] At present, the packet loss rate is one of the important indicators to measure the quality of the physical and logical links of the packet switching network. The transport network based on the connection-oriented packet switching network technology (Multi-Protocol Label Switching-Transport Profile, MPLS-TP) is For example, the packet loss rate is used to evaluate the packet loss of services on a fiber link or LSP within a statistical period, assuming that the link to be detected is a 10GBASE-ER link, and the threshold value of Signal Degrade (SD) is set for 10 -5 , the statistical period is 5 seconds (can be selected according to the link rate and detection accuracy), and the formula for calculating the Frame Loss Ratio (FLR) is: [0003] [0004] Among them: t0 ...

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Problems solved by technology

[0005] However, since the statistical period is fixed, if the required SD decision threshold is 1×10 -5 , it is necessary to ensure that the number of statistical samples (that is, the denominator in the above formula) is not less than 10 5 , otherwise less than 10 -5 detection accuracy, because the minimum number of packet loss is 1, and the FLR is less than 10 -5 , the number of statistical samples of data packets cannot be less than 10 5 , if within the collection time interval of t1-t0, the number of data packets sent by the source end is less than 10 5 , ie TxFC[t1]-TxFC[t0]5 , and the number of packet loss in this interval is 1 will result in FLR>10 -5 , and then judge that the link enters the SD state, and will report an alarm and trigger possible protection switching. In the next collection cycle, the number of packet loss is 0, resulting in FLR=0, and will exit the alarm and switching state, so an alarm will be triggered Oscillating and triggering wrong switching, which will appear in the detection period after the traffic is extremely small or after the protection switching (the service flow is switched to the standby link) or the FLR is 0 and the SD state is exited, or the FLR is large and the SD state is entered state, resulting in low detection accuracy of the packet loss rate or even detection failure

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