1. The link you provided is about LWM2M Security Object, not about how the mbed client connects to mbed Device Connector (<a href="https:&#x2F;&#x2F;connector.mbed.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;connector.mbed.com&#x2F;</a>).<p>2. To get a better feeling on how a device would actually connect to the server, here&#x27;s an easy to follow example: <a href="https:&#x2F;&#x2F;github.com&#x2F;ARMmbed&#x2F;mbed-client-linux-example" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ARMmbed&#x2F;mbed-client-linux-example</a> - this can be built &amp; run on an Ubuntu machine. (Note: there are some prerequisities, as explained in <a href="https:&#x2F;&#x2F;github.com&#x2F;ARMmbed&#x2F;mbed-client-linux-example&#x2F;blob&#x2F;master&#x2F;README.md" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ARMmbed&#x2F;mbed-client-linux-example&#x2F;blob&#x2F;ma...</a>)<p>3. You can see in main.cpp (<a href="https:&#x2F;&#x2F;github.com&#x2F;ARMmbed&#x2F;mbed-client-linux-example&#x2F;blob&#x2F;master&#x2F;source&#x2F;main.cpp" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ARMmbed&#x2F;mbed-client-linux-example&#x2F;blob&#x2F;ma...</a>) that we&#x27;re using certificate mode (line 128), and that&#x27;s also on free accounts