user80122: 
I am using a SIM808 module. It's working fine with normal MQTT over TCP, but does not work when trying secured MQTT.

I sent AT+SSLSETROOT="C:\USER\HENRY_SSL.CRT" to set the root certificate (see this document: "SIM800 Series_MQTT_Application Note_V1.03"). The response I'm getting from the GSM is: +CME ERROR: unknown.

When I try AT+SMSSL=1, I get the same error. I checked with HTTP commands and it's working fine, but the AT+HTTPSSL=1 command does not work. The SIM808 does not respond to SSL related commands.


But as per the Simcom website, the SIM808 does support SSL. Do I need to upgrade any firmware?

user80122: I updated the firmware version: 1418B05SIM808M32. Now all commands are working fine.

80122: <ol>
<li><p>I am using a SIM808 module. It's working fine with normal MQTT over TCP, but does not work when trying secured MQTT.</p>
</li>
<li><p>I sent <code>AT+SSLSETROOT=&quot;C:\USER\HENRY_SSL.CRT&quot;</code> to set the root certificate (see this document: &quot;SIM800 Series_MQTT_Application Note_V1.03&quot;). The response I'm getting from the GSM is: <code>+CME ERROR: unknown</code>.</p>
</li>
<li><p>When I try <code>AT+SMSSL=1</code>, I get the same error. I checked with HTTP commands and it's working fine, but the <code>AT+HTTPSSL=1</code> command does not work. The SIM808 does not respond to SSL related commands.</p>
</li>
</ol>
<p>But as per the Simcom website, the SIM808 does support SSL. Do I need to upgrade any firmware?</p>
 80122: <p>I updated the firmware version: 1418B05SIM808M32. Now all commands are working fine.</p>
