Conclusion:
The DCS-933L / E is not suitable for a professional alarm monitoring, because it is easy to manipulate. Power off or block the Wi-Fi and already monitoring is off.
But for the private sector it is quite good.
For example, I have the camera in the shell of a house built so that the access door is monitored. Power and Wi-Fi are available. The camera I have set so that they will send me to 8 clock 20 clock a message via e-mail when it detects a movement or a sound. The noise detection is set that the sound should be quite noisy. In the motion detection you can select the image section, which triggers the alarm. I monitor only the upper part, so that not every cat that runs through the shell wakes me.
In my alarm, the system sends 2 pictures before and 4 pictures after activation. This then I can see on my smartphone and then make up my mind whether I should go to the site or if necessary, the police have to call.
For the price I do not know any system which is as easy and quick to install.
The only point of I do not like is that I have not figured out what happened on the server with my pictures of mydlink.