RTSP is protocol for connecting of video streaming producer (camera) to consumer (recording device). After connection is opened - the transmission of video can flow via UDP packets or TCP socket.
The NetCamHD streams data over RTP - that use UDP packets. This transmission expects the perfect transmission channel (good cables, switches, short paths).
When perfect transmission channel (Ethernet) is not available - it is possible unstable Ethernet transmission it is possible to enable RTP over HTTP port.
Using this link is possible to open all camera parameters and enable RTP over HTTP:
http://_camera_ip_/cparapi/webparams.cgi