https://devzone.nordicsemi.com/f/nordic-q-a/76426/unwanted-l2cap-fragmentationHello I am in the process of developing a central BLE and I would like to be able to transmit 240 byte frames with a device. The problem I have during my tests is that I see that my packets are fragmented into small packets even though the MTU is 247en-USTelligent Community 13Thu, 17 Jun 2021 10:07:13 GMThttps://devzone.nordicsemi.com/thread/315815?ContentTypeID=1Thu, 17 Jun 2021 10:07:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e22832c3-0bfd-4318-bf7b-d6d70f42689cQuentinD<p>Hi<br /><br /></p> <p>In fact, it was not in my gatt_init () that there was a problem: the problem came from my &quot;#define NRF_SDH_BLE_GAP_DATA_LENGTH&quot; which was at 27 instead of 251</p> <p>Now it works.<br />Thank you</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/315796?ContentTypeID=1Thu, 17 Jun 2021 09:19:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d53500d5-f1a9-45f0-b025-7011352d2042Kenneth<p>Hi,</p> <p>You have increased ATT_MTU, but not DLE. So the on-air packet is still limited to 23bytes useful data.</p> <p>If you are using gatt_init() then this should be handled for you, though you can take a look at the ble_app_uart examples which I believe is doing this also. For more info also check out this blog post by third party:<br /><a href="https://www.novelbits.io/bluetooth-5-speed-maximum-throughput/">https://www.novelbits.io/bluetooth-5-speed-maximum-throughput/</a></p> <p>Kenneth</p><div style="clear:both;"></div>