Install Wireshark, VLC and a program that will find the camera on the network(this program the seller will supply).
Open Wireshark, make it start to listening to the network.
Open the program that you are using for the camera, make the image show.
Go back to Wireshark, filter for RTSP:
Search for packets like this:
Go to VLC, open a Network Stream and put there the URL found in the Wireshark(rtsp://192.168.13.157:554/onvif1):