Hey guy's. I am an old school phone guy who is desperately trying to catch up to speed with networking technology and am struggling a bit with a certain process of networking. Here is what I am trying to do... I have a Spectrum cable modem with 1 usable public static ip address. I have a cheap Netgear router that I have assigned the usable address. My computers have full internet access using DHCP, so all is good there. Doing an ipconfig, I get this from my computer...IPv4 address...10.0.0.5, Subnet...255.255.255.0, Default Gateway... 10.0.0.1. Here is where I am having an issue. I have my telephone system's voip card set as static address 10.0.0.30. I have port forwarding on the required ports necessary to the .30 address. If I plug in the IP phone directly to my router and use the "connect to" address of 10.0.0.30) it connects fine. If I take my phone offsite (and change the phone's "connect to" address to the routers public static IP), it fails to connect. I realize there are many things that could be stopping it from working, but what would be my first step in resolviong this issue? Does Spectrum need to turn my Cable modem into bridge mode for this to work? Is the port forwarding not done correctly? Any help is appreciated!

"I thought I was wrong once, but I was mistaken"