https://devzone.nordicsemi.com/f/nordic-q-a/9187/ll_feature_req---android-appHi, when using a test based on the UART app, when running it a samsung all is working just great. However, I tested it on a Nexus 7 with less luck. From the Sniffer/wireshark (screen shot attached), I see the Nexus sending LL_FEATURE_REQ and, I guessen-USTelligent Community 13Mon, 14 Sep 2015 11:17:05 GMThttps://devzone.nordicsemi.com/thread/33883?ContentTypeID=1Mon, 14 Sep 2015 11:17:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3e9f743d-623c-4d13-9dbb-66653597c83fLionel Sacks<p>Hi, Indeed - from what I can see on wireshark, I&#39;m getting a sequence like CONNECT_REQ Master-&gt;Slave : LL_FEATURE_REQ Slave-&gt;Master: Emput PDU (ie from the nRF51). five times. and then connect fail.</p> <p>I&#39;ve put screen dumps in my next question, which is probably, somehow the same issue, maybe <a href="https://devzone.nordicsemi.com/question/51149/possible-causes-of-gatt-133-0x85/">devzone.nordicsemi.com/.../</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/33882?ContentTypeID=1Mon, 14 Sep 2015 07:00:14 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2fefc590-9d43-4b87-a9e0-3b25d2252642Torsten Robitzki<p>Hi, To me it looks like, the master is not receiving an acknowlaged for it&#39;s LL_FEATURE_REQ. The next expceted sequence number in the response from the nrf51 should be the sequence number of the PDU with the LL_FEATURE_REQ plus 1 modulo 2.</p> <p>cheers, Torsten</p><div style="clear:both;"></div>