https://devzone.nordicsemi.com/f/nordic-q-a/19596/packet-loss-after-disconnectionHi All! I use nrf51822 with sd s110 to send data to android phone with sd_ble_gatts_hvx. If sd_ble_gatts_hvx returns NRF_SUCCESS then that packet get to TX buffer. I didn&#39;t find in the documentation what happens after connection lost. Are that packetsen-USTelligent Community 13Wed, 01 Aug 2018 06:48:12 GMThttps://devzone.nordicsemi.com/thread/142297?ContentTypeID=1Wed, 01 Aug 2018 06:48:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5cb134db-b6d8-49f2-81e6-a3596919140aFormerMember<p>In BLE, all packets are ack&#39;ed in the link layer. But not necessarily in the application layer: notifications are ack&#39;ed in the link layer, indications are also &quot;ack&#39;ed&quot; in the application layer.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/142280?ContentTypeID=1Wed, 01 Aug 2018 02:56:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ab0d952b-2129-4dec-b28c-2c6be2ea7b8dAndrew Ong<p>no it doesn&#39;t, the&nbsp;BLE_EVT_TX_COMPLETE indicates that it&nbsp;was transmitted, but not acknowledged. only the&nbsp;BLE_GATTS_EVT_HVC event is fired after the BLE Indication acknowledgement.&nbsp;&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/76254?ContentTypeID=1Thu, 09 Feb 2017 14:42:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:28598c78-5e4d-4b01-83ce-5e4a37bbb2a9David Edwin<p>The BLE_EVT_TX_COMPLETE event signals that the packet has been successfully transmitted and acked by the peer.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/76253?ContentTypeID=1Thu, 09 Feb 2017 13:00:20 GMT137ad170-7792-4731-bb38-c0d22fbe4515:59dd9f54-7af9-4d1c-b2c7-2f8a7ab4705aFormerMember<p>If there are untransmitted packets in the TX buffer where there is a disconnect, those packets will be lost. So, those packets will not be transmitted automatically upon a re-connect. Upon a re-connect, if needed, the packets will have to be put manually into the TX buffer.</p><div style="clear:both;"></div>