User Guide > Simulation results

Simulation results

Results window

Select the “Simulation results” in the Tab bar to view the Simulations results.

To import results data that has been saved, load a file using the File->Open menu item.

Upgrade

If the file to be loaded was generated by an older version of the application, it must be upgraded.

The simulated TCN model will be upgraded (if needed), saved to disc and the simulation will be re-run with the saved options.

Select where the model should be saved and press OK - this will load the upgraded model file and start the simulation. When the simulation finishes, the result will appear in the Simulations results Tab as usual.

     
Open Opens the result window - see below.
CSV (jitter) (If exists) Generates a CSV for the jitters in the result.
CSV (latency) (If exists) Generates a CSV for the latencies in the result.
PDF Opens the Generate PDF dialog - see below.
Save (Unless imported) Opens the Save dialog, which allow you to store the result to the hard drive.
Close Removes the row - this will also remove the file from the hard drive (unless imported).

PDF

All charts except the Gantt chart will be generated on a separate page. The Gantt chart will show the whole simulation and, depending on the page size, will spread over multiple pages.

To directly view the report in your standard PDF viewer, select the “Launch” checkbox.

Note! If the result window is open, the generated charts in the result window will be used ie all filters selections will apply.

Result window

The results are presented in a number of charts.

You can use the drag region feature in the charts to zoom into the chart. Hold down the left mouse button and drag to the right/down to mark a region. This region will be zoomed into. Hold the left mouse button and drag to the left to return to the original view.

Color codes

After Watchdogs (see below) were introduced in version 3.2, the following color codes are used for histogram bars:

Overview

The first tab is the Overview tab. Here you can view information about the simulation such as when it was started and for how long the simulation ran.

Messages

A warning message is issued if the simulator considers something happening as not being what the user wants, e.g. a Timer that has been set in the wrong place. Information is used by the simulator to communicate something that is considered as normal but the user might still want to know it, e.g. 2 connected devices have used auto-negotiation to choose common parameters in order to communicate.

Watchdogs

Different types of Watchdogs have the task of asserting that parameter values stay within user specified bounds during a simulation. Currently, you can activate watchdogs that inspect every latency and jitter value measured by a Timer (see Timer) as well as watchdogs that observe the utilization of Ethernet port transmitters (Tx) and frame memory buffers (see Ethernet Port). A watchdog will warn if any observed value exceeds an associated upper limit using a color code of red or green, as can be seen in the Watchdogs table above. Furthermore, histogram bars, in the different results charts described further below, will also be color coded green or red depending on whether an individual bar satisfies the upper limit or not.

Utilization chart

In the utilization chart you can view the capacity used by the different buses and Ethernet interfaces in the system. Since the capacity used by the ingress interface at the other end of the link is identical to the corresponding egress interface, it is not shown in the chart.

Maximum frame buffer memory utilization

This chart displays the peak utilization of Switch Port frame buffer memories registered during a simulation. The memory of an egress Switch Port stores its outbound Ethernet frames as long as they are queued up awaiting transmission to the link partner Port on the next Switch or Host. As explained in the Switch article, Switch Port memories are divided into two buffers, the high and the low frame buffer, respectively. If contention occurs on a Switch Port due to long bursts of Ethernet frames being routed through it, either or both of these buffers can reach 100% utilization resulting in Ethernet frames being dropped.

If Ethernet frames must be dropped by a buffer, these frames are registered and the number of frames dropped from each traffic flow can be inspected via a pie chart presented in a pop-up window when the mouse pointer is positioned over the chart bar of the buffer that reached 100% utilization and suffered packet drop.

Latency chart

The latency chart shows all the data collected by the Timers.

In the top scrollable list all the latency charts are thumbnailed. Hover above a thumbnail to view it as a slightly larger image. Click on it to display it in the chart panel below the list.

The chart displays latency times collected for a timer as a frequency plot. The data have been sorted into bins. A cumulative distribution function (the red curve) makes it easy to see the probablity of latency outcome (using the cross hair).

Jitter chart

Gantt Task Chart

The Gantt chart displays tasks that the different processing units have executed during simulation and between which points in time each task has been executed.

When first opening the task chart, the first 100 milliseconds will be displayed. In the case there are a large number of tasks, the chart will contain so much information that it might seem hard to overview. In this case, use the Filter panel to the right of the chart to filter out the data you want to see (the filter panel can be toggled on and off by right-clicking in the chart).

Use the Click-drag feature to zoom in the data. You can also zoom in and out by using the buttons at the lower left corner.

Use the Indicator button to toggle two slide indicators on and off. You can adjust the position of each indicator and thereby get a time difference measurement which is presented to the top left of the chart when the Indicator button is toggled on.