You should not need to do anything to set up your modem. And you don't "telnet" anything.
You have to enter the address http://192.168.1.1/ in your browser, which will open the setup for your router. You may need to change the "port forwarding" on your router so Net traffic will pass through it, and not stop at it.
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This site has a huge list of routers, with instructions how to set up port forwarding.
You may also need to tweak your firewall.
Good luck.