https://devzone.nordicsemi.com/f/nordic-q-a/72631/empty-sd-bluetooth-hvn-tx-queue-manually-connection-loss-while-transferring-dataHi, my case: I try to send as fast as possible data to smartphone. Bluetooth hvn_tx_queue_size = 20. But if I&#39;m losing connection to the smartphone, data packages are stuck in queue and if I do a reconnect, it seems like (some) data from the queueen-USTelligent Community 13Thu, 11 Mar 2021 13:24:00 GMThttps://devzone.nordicsemi.com/thread/299284?ContentTypeID=1Thu, 11 Mar 2021 13:24:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c3a29ed1-26c6-418d-881a-f8321c672c82Kenneth<p>Hi,</p> <p>On disconnect all packets are flushed in the softdevice automatically,&nbsp;so if you experience any packets are sent on re-connect then those packets are written after the connection is established.</p> <p>It is possible to send a connection parameter update request, which may also specify a preferred supervisor timeout, this can trigger the disconnect event faster if there is no communication with the peer.</p> <p>If you are in a connection with an apple device I recommend to check out chapter 36.6:<br /><a href="https://developer.apple.com/accessories/Accessory-Design-Guidelines.pdf">https://developer.apple.com/accessories/Accessory-Design-Guidelines.pdf</a>&nbsp;</p> <p>The recommendations by apple also works with other vendors is my experience.</p> <p>Kenneth</p><div style="clear:both;"></div>