iperf tool for nRF52840

[saima]

We want to use the iperf3 tool to measure packet loss while sending packets between two nRF52840 DKs. But we can't seem to find any instructions. We are using a variant of the att_mtu throughput example. Does the nRF52840 DK have support for iperf? What bluetooth protocol is used by nRF52840 DK?

Best regards

[ovrebekk]

Hi 

I agree with the reply from vham earlier. For testing packet loss I think you are better off using the DTM or radio_test examples in the nRF5 SDK, rather than trying to use the iperf3 tool. 

Maybe you can give us a bit more information about what the purpose of these tests are, and what you are trying to find out?

Best regards
Torbjørn

[saima]

Hi, sorry I have been busy. Thanks for the replies. Our purpose is to see how the throughput varies for the different phys 1M, 2M and CODED in varying distance for example: from 50 m to 1000 m, and at the same time see the packet loss between the devices. We are using two nRF52840 DKs. 

We can't seem to find any information if DTM in nRF Connect app for desktop is compatible with nRF52840 DK. If not, is it possible to incorporate code from dtm's main.c into the mtu throughput example that we are using to test throughput?

Best regards

[vham]

According to this (nRF Connect sdk 1.6.99) the diagram included in the document shows that you can connect via UART to monitor the values. As far as I remember DTM should be available for the nRF52 series, DK included.

Also, near the middle of the document you'll see instructions on Testing with nRF connect for Desktop.

There is also a pc-nrfconnect-dtm application in here (github).

Hope this helps.

[ovrebekk]

Hi

If you're interested in throughput it might be better to use the throughput example instead, since this will give you a more realistic measurement of throughput when running the full Bluetooth stack (and not just the simple DTM example). 

There should be a throughput example for both the nRF5 SDK and nRF Connect SDK, depending on which one you are planning to use going forward. 

Best regards
Torbjørn

[saima]

Yes, we are already using the throughput example for getting throughput values, which is working fine. But we would also like to get the packet loss rate between the devices along with that. Is there a way to do that without DTM?

[ovrebekk]

Hi 

I don't think there is any easy way to do that without DTM, no. 

In theory it is possible to estimate packet loss based on how much data you get through on every Bluetooth connection event, since any lost packet will immediately end the connection event, but since the link layer handles all of this for you you don't have a lot of visibility into what is going on. 

If you want an accurate measurement of packet loss I believe DTM is the best option. 

Best regards
Torbjørn