I have done some clear examples for Cactus Rev 2 in my blog here: gideonvos.wordpress.com and also use it extensively with example code here: www.iotlink.net. Feel free to copy and use the examples if it helps you in any way.
Because the code is for Arduino Mega. So just replace Serial2 to Serial1, it should work with Cactus. I'll add the example to our wiki.
Thank you very much for your sharing.
Correct, on my blog it is a Mega, but if you visit my site at http://www.iotlink.net and click on Learn More, then Examples, there are examples for Cactus rev 2 using both SSL and non-SSL to post REST messages.