viSar camera integration through ONVIF


I have a couple NVR’s which aren’t connected to the same ip( f. e. 192.168.1.x and 192.168.2.x). I am able to read the OnVIF devices on the same IP for example the HA server is connected on 192.168.1.x so i can access NVR’s that are connected to that, but I am not able to connect to the other NVR’s. Has anyone had this kind of problem?
Maybe somebody integrated viSar NVR’s seperately?