Measuring Bandwidth Usage

On the FRC® Field (and at home when the radio is configured using the FRC Bridge Configuration Utility) each team is limited to 4Mb/s of network traffic (see the FMS Whitepaper for more details). The FMS Whitepaper provides information on determining the bandwidth usage of the Axis camera, but some teams may wish to measure their overall bandwidth consumption. This document details how to make that measurement.

Measuring Bandwidth Using the Performance Monitor (Win 7 only)

Windows 7 contains a built-in tool called the Performance Monitor that can be used to monitor the bandwidth usage over a network interface.

Launching the Performance Monitor

Using the start menu to type "perfmon.msc".

Click Start and in the search box, type perfmon.msc and press Enter.

Open Real-Time Monitor

Click "Performance Monitor" under "Monitoring Tools" in the tree view.

In the left pane, click Performance Monitor to display the real-time monitor.

Add Network Counter

The "Add Counters" screen showinging the steps below.

  1. Click the green plus near the top of the screen to add a counter

  2. In the top left pane, locate and click on Network Interface to select it

  3. In the bottom left pane, locate the desired network interface (or use All instances to monitor all interfaces)

  4. Click Add>> to add the counter to the right pane.

  5. Click OK to add the counters to the graph.

Remove Extra Counters

Removing the counter at the bottom of the graph screen.

In the bottom pane, select each counter other than Bytes Total/sec and press the Delete key. The Bytes Total/sec entry should be the only entry remaining in the pane.

Configure Data Properties

Scale dropdown highlighted on the Performance Monitor Properties page.

Press Ctrl+Q to bring up the Properties window. Click on the dropdown next to Scale and select 1.0. Then click on the Graph tab.

Configure Graph Properties

Moving to the Graph tab the Maximum field under Vertical Scale is highlighted.

In the Maximum Box under Vertical Scale enter 917504 (this is 7 Megabits converted to Bytes). If desired, turn on the horizontal grid by checking the box. Then click OK to close the dialog.

Viewing Bandwidth Usage

Observing the bandwidth usage on the chart screen.

You may now connect to your robot as normal over the selected interface (if you haven’t done so already). The graph will show the total bandwidth usage of the connection, with the bandwidth cap at the top of the graph. The Last, Average, Min and Max values are also displayed at the bottom of the graph. Note that these values are in Bytes/Second meaning the cap is 917,504. With just the Driver Station open you should see a flat line at ~100000 Bytes/Second.

Measuring Bandwidth Usage using Wireshark

If you are not using Windows 7, you will need to install a 3rd party program to monitor bandwidth usage. One program that can be used for this purpose is Wireshark. Download and install the latest version of Wireshark for your version of Windows. After installation is complete, locate and open Wireshark. Connect your computer to your robot, open the Driver Station and any Dashboard or custom programs you may be using.

Select the interface and Start capture

Selecting the Start button and choosing the NIC in Wireshark.

In the Wireshark program on the left side, select the interface you are using to connect to the robot and click Start.

Open Statistics Summary

In the menu bar at the top choosing "Statistics" then "Summary"

Let the capture run for at least 1 minute, then click Statistics then Summary.

View Bandwidth Usage

Looking at the "Avg. MBit/sec" field of the Wireshark summary.

Average bandwidth usage, in Megabits/Second is displayed near the bottom of the summary window.