ntopng provides historical views on the recorded timeseries data .
From the top left dropdown it’s possible to select the timeseries data to display. Other than the actual timeseries data, the chart will also show:
A comparison serie with the past. In the picture above, 30m ago will show the interface traffic 30 minutes ago.
A trend line, which indicates the trend of the total traffic in the specified period. This is based on the https://github.com/stanford-futuredata/ASAP algorithmn.
A SMA line, for the Simple Moving Average of the traffic. This performs an average on the traffic trend by smoothing it.
An EMA line, for the Exponential Moving Average of the traffic. This reacts to trends changes more quickly then the SMA.
An RSI line, for the Relative Strength Index on the difference between now and the past. Usually an RSI value above 70 indicates a major increase of the traffic wrt the previous period, whereas an RSI value below 30 indicates a major decrease.
The average line, a straight line outlining the average value for the timeseries.
95th percentile, a straight line outlining the 95th percentile value of the traffic. It indicates the value for which 95% of the timeseries points are below it.
By using the time selectors is possible to specify a specific time frame to graph. It is also possible the predefined resolutions to display the latest data for predefined intervals, e.g. latest 5 or 30 minutes. By clicking on -30 and +30 buttons is also possible to jump to the corresponding interval in the past or future.
Timeseries data is shown on the charts is sampled. In order to get more accurate data is necessary to zoom into the chart. This can be performed easily by dragging the mouse on the specified interval; chart will update dynamically and show the interval data with higher resolution. A double click on the chart performs a zoom out.
By clicking on the icon it’s possible to get a permanent link to the current view to share with others. If traffic recording is enabled, by clicking the icon it’s possible to download a PCAP file of the interface or host traffic in the specified time frame. Depending on the selected historical timeseries, this could be available or not.