Airtel Xstream Zyxel PMG5617-R20B ONT Port Forwarding

That's unfortunate. I only got the router switched, I could forward ports on the previous router easily. I'll see if I can get the technician to give me another router of the older model


I'm forwarding ports 8096 and 3389 for my media server and remote desktop respectively, and I was forwarding ports successfully even with dynamic IP with my previous router, I'm not sure how the change of router caused me to go from dynamic public IP to CGNAT, but I'll try to contact them
I've been reading such responses that help users one way or another. Is there a resource for understanding the essentials of home networking and troubleshooting, that specifically addresses the issue of port forwarding, mac binding, etc.?

Airtel doesn't respond to queries that ask for control of routers.
 
Recently due to some connection issue where my speeds would go down from 40 mbps to 2-3 mbps after half an hour of restarting the router, the Airtel technicians changed my router from the Nokia ONT to a Zyxel PMG5617-R20B. There's an option to forward ports inside this router's configuration page as well but it's not taking hold because I can't access my media server from outside the network. Microsoft Remote Desktop isn't working either. Has anyone successfully gotten port forwarding to work on this model?
actually airtel doesnt give you a static ip by default but ive tried contacting them and they said you need to purchase a static ip and it will cost u 100rs more than ur current plan