The Lorex LHB927 supports RTSP streams which have routes:
ch1/0 for camera 1
ch2/0 for camera 2
...
They start counting from 1, not 0.
Alternatively, they can also be reached at:
ch1_0
ch2_0
...
Adding more routes (for cameras #3 & 4) increases the odds of finding the DVR, if for example, camera 1 is offline.