Need help setting up Orange Network

Greetings, any assistance would be greatly appreciated.

I’ve been trying to set up a Red/Orange/Green zoned layout with three ethernet interfaces. What I’m trying to do is to put a SIP server on the Orange network that will be accessible from both the Red and the Green networks. So far I’ve had no success getting any traffic to the server from the red network. Here is a diagram of the layout:
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I’ve tried to follow the “Setting up DMZ” Instructions
(https://wiki.ipfire.org/optimization/setting_up_dmz) without any success.

Would someone help me figure out how to construct the firewall rules to accomplish this scenario?

Thank you!

Look here

ignore the word green, change 80 to what you need. And Destination 10.1.1.10.

Also you can read Creating a Port-Forward Rule.