l try to request before performing DFU. By default, value 517 will be used, which is the highest supported by Android. However, as the highest supported MTU by the Secure DFU from SDK 15 (first which supports higher MTU) is 247, the sides will agree on using MTU = 247 instead if the phone supports it (Lollipop or newer device). </p><p class="paragraph"> The higher the MTU, the faster the data may be sent. </p><p class="paragraph"> If you encounter problems with high MTU, you may lower the required value usi