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Packet Sniffer does not receive all packets

Ahmad Manjur -E- Khuda
Prodigy 125 points
Other Parts Discussed in Thread: CC2540

Hi,

I am using Packet Sniffer with CC2540 usb dongle as analyzer to analyze Bluetooth LE packets. As I understand Packet sniffer is scanning and receiving data only in the advertising channels. I have only one initiator and one advertiser. Once the connection is established between the two devices, I don't see anything in Packet sniffer. Probably because after connection establishment, communication is continued in a different channel. 

Is it possible to make Packet Sniffer to analyze all packets even after the connection is established? Cannot it analyze other channels? Is there any way I can manually switch channels?

Thanks.

  • 0
    Prodigy 190 points

    Hi,

       No one know? I also encounter this problem.

       Who can help me?

      Thanks?

  • 0
    Intellectual 785 points
    The sniffer normally listens on one of the three advertising channels. It will hear all advertisements because devices generally transmit advertisements on all three advertising channels. If the sniffer observes the connection being set up between the two target devices it will then follow them as they change channels and you will see all the subsequent packets in that connection. However, if the connection setup occurs on one of the two advertising channels that the sniffer is not listening to it will not realise that a connection has happened, and it will continue to listen to the one advertising channel, and you will not see any subsequent packets. In general, you can expect the sniffer to successfully observe and then follow about one in three connections. If you want it to always succeed you can either: (i) Buy two more sniffers and have one listening to each advertising channel. You can configure which advertising channel each sniffer listens to in the software. (ii) Configure your device to only transmit advertising packets on the one advertising channel that your sniffer is listening to. This ensures that it must hear the connection set-up.
  • 0 in reply to Matthew Kendall
    Prodigy 125 points

    Yes it may hear the connection set up but after the connection is set up, nothing is received. I want to see all packets after the connection is set up. It is not possible by packet sniffer. Is it?

  • 0 in reply to Ahmad Manjur -E- Khuda
    Intellectual 330 points

    like  said

    you can buy two more sniffers and have one listening to each advertising channe.(I.E.  the first one sniffer listening 37 channel，another one listening 38 channel，the last one listening 39channel.when connected （I.E.  after the connection is set up）you will see all packets by the first one,or the another one or the last one）

    another method is you can configure your device to only transmit advertising packets on the one advertising channel that your sniffer is listening to （E.G. only advertising on 37 channel，or only advertising on 38 channel，or only advertising on 39 channel 。 your sniffer must be  listening to the same you configured）