Is someone trying to connect into your computer using Echolink, or are you trying to make a connection to someone else's computer?
If someone is trying to connect to your machine from the outside, you may want to look at your Wireless router as provided by the FiOS service. The router will block connections it isn't told about coming in by design, and what you need to do besides checking your computer's firewall, is to Port Forward. If you're making the connection from your end to another person or server, then the person on that end has to make sure they've done Port forwarding and firewall checks, as needed.