Full packet not written to pcap file

[mkabjian]

Full packet not written to pcap file

[mkabjian]

Thank you for your response. Yes I was just looking into this. I thought BT5 extended advertisements were larger based on the Opendroneid spec and sample data. My guess is the transmitter implementation is chunking the data into smaller advertisements.

I apologize for erroneously opening an issue. I will work on decoding the packets and confirm this is a transmitter issue and not Sniffle. Thanks again for your great work!

[sultanqasim]

I’m not sure how 271 byte packets would be transmitted. The maximum PDU size for BLE is 255 bytes plus a 2 byte header and 3 byte CRC (not included in Sniffle’s output but it is checked by the hardware). Could you share a PCAP of what you’re seeing?

[sultanqasim]

If it's using BT5 extended advertising, you could achieve longer advertising with AUX_CHAIN_IND PDUs, for example doing a 255 byte chunk followed by a 16 byte chunk. Is the sniffer properly following AuxPtrs in ADV_EXT_IND and AUX_ADV_IND PDUs you see? You're using the -e flag with the sniffer?

[mkabjian]

This was not problem. It was just a misunderstanding of the proper packet size from the opendroneid spec. We have the packets decoding fine now.

I was using -e and -e -l with the sniffer and the packets look good.