https://devzone.nordicsemi.com/f/nordic-q-a/15741/gatt-s110-mtu-sizeHi again, I posted earlier in another post that my writeCharacteristic is responding with status 6. Details: Android version: 5.1 Nordic device: nRf51822 S110 I have increased my device mtu size to 512, same needs to be done at device end. Isen-USTelligent Community 13Mon, 15 Aug 2016 11:03:04 GMThttps://devzone.nordicsemi.com/thread/60094?ContentTypeID=1Mon, 15 Aug 2016 11:03:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0698aef0-cdfd-464c-82e6-d914b8cfe9a8Hung Bui<p>@Samra: Could you provide more information about the issue you have ? Error 6 means GATT_REQUEST_NOT_SUPPORTED. Are you sure you used the correct handle ID and the characteristic support write request ?</p> <p>I assume you increased MTU size to 512 on Android side. On the nRF51 is&#39;t not possible to change the MTU from 53. Start from S132 v3.0 (for nRF52) you can increase the MTU to maximum 512.</p><div style="clear:both;"></div>