I'm looking into getting a Dahua video doorbell VTO2111D. I would like to know if I can hook this up to my existing Dahua NVR that I already have and if I can access all the features such as remote answering from my phone and surveillance at the same time. I've already set up my cameras on GDMSS App and I was assuming that this can be done with the video doorbell added on as well. My NVR I have is the NVR2108- 8P. Any help appreciated.