NetTraffic shows 9Mbit/s even though router limited to 7

Technical Technical Discussion
1

I’m tuning the camera code for the 7Mbit/s bandwidth restriction, so I flashed the router to limit it (using the tool), the camera and communications work smoothly, but a bandwidth measuring program (NetTraffic) displays about 8-9 Mbit/s. Is the router restriction broken? Or is it NetTraffic?

If it works now will it work at the competition?

See attachment.

Thanks!

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2

I dont think the router firmware limits your bandwidth, nor will the field at competitions. That limit is just FIRST asking you to keep it below that. If you go over the FTA will tell you to get it below 7.

3

I believe there is an FMS limit

A significant increase in Average Trip Time occurs just above 6Mbps of data because there is already ~900Kbits/sec being consumed by the DS-Robot packets alone. Network congestion increases as you approach the 7Mbps limit of the VLAN and as a result the Average Trip Time increases. The QoS policy described above works to prioritize control packets specifically to allow for some reasonable level of Robot control to be available under such conditions, but performance cannot be guaranteed.
For the 2020 season software documentation has been moved to https://docs.wpilib.org. Documentation for KOP items can still be found here. | FRC KOP Documentation

I would presume that NetTraffic is working correctly, and limit yourself to 6Mbps. That would be the conservative thing to do. What does your Task Manager show?

Note: I believe there is some FMS-Robot communcations happening that only shows up at competition. Limiting yourself to 6Mbps would leave room for that.

4

In reality you don’t want to come close to 5mb/s. Bandwidth rates are an approximation and you may go past the limit for less than a second. They are controlled on the main FMS router through some QoS features. 7mb/s is the programmed limit but everyone on the field crew is watching for numbers greater than 5.

5

The router only limits your bandwidth if you checked the “BW Limit” when programming your router at home. I’d recommend refreshing the configuration to double check that.