https://devzone.nordicsemi.com/f/nordic-q-a/41965/nrf52-throughput-testHello, I&#39;m testing the ble_app_att_mtu_throuput example on SDK15.2, I found that the throughput becomes very fast by just changing the &#39;data_length&#39; from 27 to 251 compared with the default configuration. Default configuration : ATT MTU = 247en-USTelligent Community 13Wed, 02 Jan 2019 14:56:03 GMThttps://devzone.nordicsemi.com/thread/163496?ContentTypeID=1Wed, 02 Jan 2019 14:56:03 GMT137ad170-7792-4731-bb38-c0d22fbe4515:57a683f5-8eb2-435c-9e43-e6a1102399e6Bj&#248;rn Kvaale<p>Hi Mehdi,</p> <p>By increasing the data length (data length extension, DLE), you are increasing the number of bytes that can sent in each on-air packet. If you do not have a lot of wireless interference, it can be very quick to set the DLE to 251. If you have a lot of wireless interference, it can be better to use a smaller value because if a packet does not arrive, the contents of that packet need to be retransmitted.</p> <p>The reason that ATT MTU is less than the DL is because there are 4 header packets that cannot be used to send data on (link layer header I believe).&nbsp;</p> <p>The best idea is to read <a href="https://devzone.nordicsemi.com/b/blog/posts/throughput-and-long-range-demo">this blog post</a> carefully. Everything is explained very well there.</p> <p>Kind Regards,</p> <p>Bjørn</p><div style="clear:both;"></div>