https://devzone.nordicsemi.com/f/nordic-q-a/90594/discovery-get-handle-of-first-characteristic-by-service-uuidWe have a custom service on our server/peripheral devices, with a number of characteristics. This service is implemented on a number of host platforms, including nRF devices, TI devices, uBlox devices, Android, iOS etc. Our custom service structureen-USTelligent Community 13Mon, 08 Aug 2022 13:49:29 GMThttps://devzone.nordicsemi.com/thread/380636?ContentTypeID=1Mon, 08 Aug 2022 13:49:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4a41761c-077f-4e70-bcec-75857a2fcc37Sigurd<p>Hi,</p> [quote user=""]Is this the DB Discovery library the most efficient way of doing what we want on the nRF platform or are there other alternatives? Secondly, how does it work/are there any indications on performance before we embark on the development?[/quote] <p>Here you can see what happen on-air between the BLE UART peripheral and central examples, where the DB discovery module discovers the NUS service and enables the notifications. Also note that if you bond with the device, no service discovery is needed in&nbsp;subsequent connections between the devices.</p> <p><span>(Sniffer trace captured&nbsp;using <a href="https://www.nordicsemi.com/Products/Development-tools/nRF-Sniffer-for-Bluetooth-LE">nRF sniffer </a>)</span><br /><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/5826.pastedimage1659966342011v1.png" alt=" " /></p> <p>If you find that the DB Discovery library does not offer the performance you want, then perhaps using the SoftDevice API directly could be a solution.&nbsp;<a href="https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.3.0/group___b_l_e___g_a_t_t_c___f_u_n_c_t_i_o_n_s.html">https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.3.0/group___b_l_e___g_a_t_t_c___f_u_n_c_t_i_o_n_s.html</a></p><div style="clear:both;"></div>