If this metric is zero, that indicates there is likely a problem with the span port or network taps that are collecting traffic for the appliance. If, at the same time, the metric is greater than zero, that indicates that the appliance is seeing only one-way traffic from client to server, and is not seeing the server-to-client traffic.
The agent reassembles TCP segments into complete messages before it begins its analysis. In this process, missing segments that are needed to build a message can be detected. This metric indicates the number of segments in the server-to-client traffic that the agent has determined are missing. Check the metric to see the rate at which client segments are missing as a percentage of the total number of segments.
This metric shows the percentage of server segments that are missing out of the total number of segments have been processed. In ideal circumstances, this metric would always be zero. In practice, a small percentage of missing segments is typical.
The and metrics are used in the calculation of this metric.