https://devzone.nordicsemi.com/f/nordic-q-a/27620/how-to-get-acknowledgement-confirmation-after-sending-an-indicationHi, We are sending a data using Nordic UART Service (NUS), the data is transferred over BLE as a Indication. From Message Sequence Chart in Nordic Infocenter Here it shows ATT Handle Value Confirmation(blue arrow from PEER to SD). I haveen-USTelligent Community 13Tue, 28 Nov 2017 13:58:34 GMThttps://devzone.nordicsemi.com/thread/109086?ContentTypeID=1Tue, 28 Nov 2017 13:58:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fac5ba0d-4fb8-4046-9438-fe3b4e47d87covrebekk<p>Hi</p> <p>The idea behind the indication is that is has to be confirmed by the application, the SoftDevice won&#39;t do it for you.</p> <p>To do so you have to call the <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v5.0.0/group___b_l_e___g_a_t_t_c___f_u_n_c_t_i_o_n_s.html?cp=2_3_1_1_0_2_2_2_7#ga173e2d16c9bbd24dcf2c724ded6708a5">sd_ble_gattc_hv_confirm(..)</a> function, after receiving the BLE_GATTC_EVT_HVX event.</p> <p>The main purpose of indications is to allow the application to confirm the packet only after it has fully processed the data, and completed any operations associated with it.<br /> If quick and efficient data transfer is more important I would recommend using notifications instead, you still have a link layer ACK to avoid packet loss/corruption.</p> <p>Best regards<br /> Torbjørn</p><div style="clear:both;"></div>