https://devzone.nordicsemi.com/f/nordic-q-a/83335/how-to-increase-mtu-of-nrf52840-to-247Hi there, I am developing a peripheral to central system with nrf52840 base on NUS service. Now I tried to increase the MTU of the peripheral to 247 to increase the transfer rate. I modified the NRF_SDH_BLE_GATT_MAX_MTU_SIZE to 247 and NRF_SDH_BLE_GAP_DATA_LENGTHen-USTelligent Community 13Wed, 05 Jan 2022 08:39:07 GMThttps://devzone.nordicsemi.com/thread/346055?ContentTypeID=1Wed, 05 Jan 2022 08:39:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a37a2fc5-2709-4ac0-8584-5043a7a984aaSimonr<p>Hi</p> <p>The 31 bytes you&#39;re seeing is only the advertising packet transmitted over BLE (you can see this from the info column in Wireshark). The MTU size is negotiated and set once the device connects to a device and is ready to transmit data in the connection. If you want to increase the size of your advertising packet you should check out extended advertising in <a href="https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/bluetooth-5-advertisements-extended-and-periodic-a">this blog post</a>.</p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>