Yes you can have as many IP cameras as your network can handle (including the 6564), however the more cameras you have, the more bandwidth is used. The average home network is not equipped to run many IP cameras at full settings, therefore the more you have the lower you will have to set the frame rate, bit rate, and possibly resolution. With IP cameras on the apps, you would have to set up an individual profile for each since they would each have their own assigned IP address to connect to, as well as their own port, which only allows you to view one at a time. To view all the IP cameras at once you would need a device such as an NVR (Network Video Recorder), thereby attaching each camera to the NVR and grouping all of the individual cameras under one IP address, the one assigned to the NVR. You could then use an app to pull up the NVR and view all the cameras attached to it.