SmartGlas does not require port forwarding to my knowledge as it should work using HTTP which, ideally, should already be correctly forwarded by your router. However, specific games require specific ports to use SmartGlass as companion applications. You should check these game's pages for more information.
All in all, there is a bigger flaw in your plan. SmartGlass has been designed to work on LAN, not WAN. Your IP is likely not static making it pain to keep track of it. And even if you could track it, the IP might not be public and your ISP may have therefore made it impossible for you to remotely connect to your LAN. I believe your best bet is to try and establish a Virtual Private Network. Still, I think the endeavour is highly doubtful.
What would you like to use this for if I may inquire? There might be an easier way to accomplish it.