RE: need wireshark usage examples

efiLabs — Tue, 16 Jan 2018 20:46:50 GMT

thanks shibshab :

this was exactly what i was looking for and i'm sure lots of others will also appreciate it

RE: need wireshark usage examples

efiLabs — Tue, 16 Jan 2018 09:34:40 GMT

thank you thank you thank you ... your explanation looks great ... i'll have a look tomorrow, right now it's 1:30 am California time i don't think i saw anything as detailed as this more tomorrow :) cheers Klaus

RE: need wireshark usage examples

shibshab — Tue, 16 Jan 2018 07:23:54 GMT

First of all, when sharing traces you should send the entire trace file. This is saved by clicking File -> Export ... and then choosing the packets you want to export.

To see the data contained in each packet, simply highlight one packet by clicking it, and see the Packet Details panel for more details. If you do not see this, click View -> Packet Details. This will show all data in the packet dissected and put in context of each of the different protocols being used.

To see when a connection interval ends, its easiest to add the Nordic BLE Sniffer -> Delta Time (us end to start) as a column and keeping in mind that all packets within a connection event is sent with 150us between them, as shown below.

As for your issues with overflow I do not know, how are you sending the data?

To find the connection interval, the simplest way is to inspect the contents of the CONNECT_REQ packet (#38 in your trace). See an example below

Alternatively, you can set up a filter. ALL fields you see in the Packet Details view can be used for filtering. The filter I will make to find the connection interval is:

The packets need to be NON-advertisement packets (I.E. from a connection.) So I add btle.access_address != 0x8e89bed6 since this will filter out any advertisement packets as they all have the access_address 0x8e89bed6.
I want to see only master packets (as they dictate the start of the connection interval) So I add nordic_ble.direction == 1
Lastly I want to see the time between each packet I now have displayed, so I add a new column using a field from the Packet Details View, namely Frame -> Time Delta from previous displayed frame. You can also a field from the sniffer Nordic BLE Sniffer -> `Delta Time (us end to start).

Below is a trace with 30ms connection interval.