Spring RTS Engine

Is it possible?Or i got to buy external ip,or autohost?

depends. most of the time "hole punching" in hosting options works.

Forward the port you use to host games to your PC.

Huh, it would definitely be easier to have a public IP address... based on what your saying it sounds like your ISP has provided you a private-only IP address, is that correct?

Some ISPs don't charge for the first IP address and may be nice enough to set up port forwarding for gaming purposes or give you access to the combo modem-router you have... also, many combo modem-routers have default usernames/passwords which you can find online, though check your ISP's official policy on the matter...

there's a program Called "Hamachi" currently available for free for non-comercial use through LogMeIn ( https://secure.logmein.com/products/hamachi/vpn.asp )

it basically set's up a virtual VPN to which anyone can connect, essentially you (or someone in a similar situation as you) could set up a hamachi network and run a Spring server on it and then anyone could connect to this hamachi network with their Spring client software and games could be set up... I'd look into it myself but I share an internet connection with the business I'm renting the apartment above so it would need to be off from 9am to 6 everyday.