Under some conditions, data collected from a device may be in an inconsistent state.

Calculations using the inconsistent data may be negative our outside the expected range.

Negative value seen for graph of quantity of traffic throughput

Ignore the negative values.

The negative values are captured for "in-mbps" which is calculated using the rate of change formula from the field "input-bytes". The in-mbps field values are appearing as negative values in the DB. this can happen when the "input-bytes" from the device corresponding to the interface is not consistent over time.