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Problems following BLE connection

Question asked by Phillip Beeson on Jul 19, 2017
Latest reply on Aug 11, 2017 by Phillip Beeson

I'm trying to use the USB-KW41Z dongle to sniff a simple BLE 4.1 connection.   The advertising frames and scan request\response frames are captured and decoded with no problems.  However, when I capture a connect request, the sniffer seems unable to follow the connection.  Sometimes it immediately fails, with the frame immediately following the request being [mis] identified as a 285 byte L2Cap fragment, other times there are a few frames decoded and others not and then the packet capture stops, even though I can see the devices are still maintaining the connection.

 

I've attached a couple of capture files in case anyone more familiar with this than me can figure out what's going on. The connect_capture_kw41z is an immediate fail on the frame following the connect request

The kw41z_fail is an example of a partial capture before failure. 

 

I both cases I see decodes in the Kietis Adapter Information disector output that indicates the channel number being one that wasn't included in the channel map of the connection request, and also incorrect access address in the BLE link layer decode, so I'm assuming the data from the dongle is mis-decoded and/or the output of the dongle is junk.

 

I've tried this with a Nordic semiconductor sniffer and I can capture all the packets no problem, but I ultimately want to use the KW41Z to sniff BLE 4.2 with an extended MTU  (Data Length Extensions).

 

Does anyone have any suggestions ?

 

Win7 64bit

Kinetis Protocol Analyzer Adapter v1.2.4.0

Wireshark 2.2.7

 

Thanks,

Phil.

Original Attachment has been moved to: kw41z_fail.pcapng.zip

Original Attachment has been moved to: connect_capture_kw41z.pcapng.zip

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