https://devzone.nordicsemi.com/f/nordic-q-a/21756/in-gatt-packet-transfer-is-there-occurs-any-packet-loss-and-retrialIn GATT Packet transfer, is there occurs any packet loss and retrial? I&#39;m trying to connect about -90 Rssi dBm peripheral device with my nRF51-dk. In this far range, does it may occur with packet loss in this far range, and if there is packet lossen-USTelligent Community 13Wed, 03 May 2017 03:22:32 GMThttps://devzone.nordicsemi.com/thread/85440?ContentTypeID=1Wed, 03 May 2017 03:22:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7036b77b-ac45-47da-bcdb-3e04629c5d89RK<p>BLE link layer is guaranteed to deliver reliably and in order and it will retry as often as it needs to to uphold that guarantee. Eventually if the link fails to get a packet across it will timeout and fail. Those are the only two possibilities.</p> <p>You can&#39;t tell if it retried a packet from anything on the user side, you can run a sniffer and look to see if the underlying BLE packets are re-transmitted, or you can deduce it from the amount of data you&#39;re getting down the link.</p> <p>You can&#39;t change the retry count. This is all part of the BLE link layer spec.</p><div style="clear:both;"></div>