Throughput calculation with Wireshark

RE: Throughput calculation with Wireshark

Simonr — Fri, 29 Jan 2021 08:35:31 GMT

Yes, there will be a "roof" in nRFConnect as well, as the data will have to be processed and sent to the app there as well. You can use this ble_app_uart_throughput example made by one of my colleagues to test what throughput you're able to achieve.

devzone.nordicsemi.com/.../6303.nrf5_5F00_sdk_5F00_17.0.2-_2D00_-ble_5F00_app_5F00_uart_5F00_throughput.zip

Best regards,

Simon

RE: Throughput calculation with Wireshark

WaKo — Thu, 28 Jan 2021 21:54:34 GMT

Thank you your answer.

I understood about Wireshark.

How about nRF Connect for Desktop ?

May using it with nRF52840 dongle as a master also face missing a few packets ?

Best regards

RE: Throughput calculation with Wireshark

Simonr — Thu, 28 Jan 2021 07:20:40 GMT

At this maximum throughput in the 2MBPS PHY and with DLE + L2CAP, the nRF Sniffer will fill its buffer rather quick, and while it sends data from the chip to Wireshark, the device will miss a few packets before getting back to listening.

Yes, you can estimate a throughput rate from Wireshark using the delta time and packet time parameters.

Best regards,

Simon

RE: Throughput calculation with Wireshark

WaKo — Wed, 27 Jan 2021 14:01:55 GMT

Thank you for your answer.

> On the 2MBPS PHY with DLE and L2CAP, it is confirmed that the nRF Sniffer will not be able to send all the data from the chip over to Wireshark in time, indeed.

Dose this means that nRF Sniffer sometimes can't send data to Wireshark in time but all the data are captured and sent to Wireshark ?

If I calculate throughput rate from Wireshark, using "delta time" and "packet time" is the most accurate way ?

Best regards

RE: Throughput calculation with Wireshark

Simonr — Tue, 26 Jan 2021 09:12:07 GMT

As I think you might see, Wireshark receives the data ~5 packets at a time in your case. On the 2MBPS PHY with DLE and L2CAP, it is confirmed that the nRF Sniffer will not be able to send all the data from the chip over to Wireshark in time, indeed. In more high-end Sniffer solutions, like Ellisys and Frontline should be able to capture all packets at this data rate.

The Packet Time you are referring to shows the time that the packet itself uses on air.

Best regards,

Simon

RE: Throughput calculation with Wireshark

WaKo — Tue, 26 Jan 2021 05:27:24 GMT

Thank you for your reply.

> This parameter is at what time each packet is received over the COM port to Wireshark

If nRF52840 dongle working as sniffer receives large data many times in a row how dose it works ?

May sniffer fails to receive some data because on-air transmission is faster than transmission over COM port ?

"Packet time" is here(see attached picture)

RE: Throughput calculation with Wireshark

Simonr — Mon, 25 Jan 2021 10:20:46 GMT

Your assumption that time is incorrect in regards of data transmission is correct. This parameter is at what time each packet is received over the COM port to Wireshark, and has nothing to do with the on-air transmission per se.

Delta time should indeed show the correct time that each radio event takes to complete, so that should show you the correct time between each advertising packet. As for the "Packet time" you are seeing, I don't have this parameter on my Wireshark, can you show me what "Field" this is in the Wireshark "Column preferences"? You can get to the menu pictured below by right-clicking any of the columns in Wireshark and press "Column preferences" in the dropdown menu.

Best regards,

Simon