I found in the AT command guide a useful command “AT+CIPACK” I get the response after I send my Connect Packet:
AT+CIPACK +CIPACK: 230,230,0
My calculated “Remaining Length” is 228. Add the “0x10” start byte and the “Remaining Length” byte itself and that makes 230. So that sounds correct.
From the SIMCOM manual:
The command AT+CIPACK is used to query previous connection data transmitting state. In single connection, the execution command AT+CIPACK will return +CIPACK: ,, . The first parameter is the data amount which has been sent; the second parameter is the data amount confirmed successfully by the server; and the third parameter is the data amount without confirmed by the server. As long as the connection is still active, user can know how much TCP data user sent to server and how much is received successfully by the server in total. By this means, user can get the total data transmitting amount.
Perhaps this is an indication that the SSL connection is working?
Though I still have no response from the Azure server.