nRF Sniffer V2.0 shows wrong delta times

[JB21]

I just upgraded to nRF Sniffer V2.0

The Time column of Wireshark shows wrong values for short delta times. Is is set to "seconds to previous packet"

My advertiser runs at 20ms, nRF Sniffer V1 displayed it correctly.

But V2.0 shows way to small values, while the metadata in the right pane contains the proper values. See Sniffer1.png

After a while the time column shows a much larger value (100 ms), while the metadata shows 500us as expected. (green arrow) It seems it tries to catch up with the delay.

Any idea how to fix this?

[David Edwin]

The time column is the packet arrival time over the USB interface to the PC and is timestamped on the PC. I would typically expect some differences due to buffering and other jitter on the USB bus and if the PC is loaded more heavily to have more jittering.. The delta time (us end to start) (which you call as metadata) is timestamped in the sniffer so should be more reliable. I typically use the sniffer with the metadata applied as a column. See attached screen shot of my wireshark setting.

[JB21]

Thank you, just what I needed. I took me a while to figure out how to configure that.

[twhiting87]

Hi David, I'm needing to add the delta time (end to start) as a column as you have above, but cannot figure out how you added the metadata as a column. Would you be able to post on here how you did this?

Thanks,

Tom

[twhiting87]

Sorry David, just figured it out (was easier than expected). For anyone that wants to know:

Edit -->Preferences --> Appearance --> Columns

Click on the + and Name the column under title. Change Type to Custom and then put nordic_ble.delta_time under Fields and 0 under Field Occurrence.