Port Forwarding for RTSP Stream

Hello,

I have read through and followed the suggestions on other posts regarding port forwarding (NAT) within UTM 9 however, I cannot seem to get things to work.

I have three internal cameras with which I need to allow external access to their RTSP streams. The internal url for these feeds are as follows:

rtsp://192.168.1.30:554/11
rtsp://192.168.1.28:554/11
rtsp://192.168.1.32:554/11

Using my single external IP address, I will need to specify a different port and then forward for each camera such as:

rtsp://200.13.12.42:2007 => rtsp://192.168.1.30:554/11
rtsp://200.13.12.42:2008 => rtsp://192.168.1.28:554/11
rtsp://200.13.12.42:2009 => rtsp://192.168.1.32:554/11

I have tried to accomplish this numerous ways and I am still unable to view these streams externally. Internally, the streams function perfectly. How do I go about configuring this correctly? Thanks in advance for any assistance.