官方网站的信息：
1 september 2007: the echolink system now has features that make it more "firewall-friendly", when used with version 2.0 or above. this is particularly useful for users who are operating at internet hot-spots, or who have certain types of satellite or wireless internet service. for details, see echolink, routers, and firewalls.
注意：不是所有的路由器和防火墙都有效
does this new feature work with all types of routers and firewalls?
a: no; it only works with the most common types of nat routers, such as the type typically found in home networks. if you have some other type of firewall, including software firewalls such as norton internet security, you will still need to take extra steps to allow the echolink software to work correctly. this feature also might not work with more restrictive firewalls such as the type found in offices and businesses. in these situations, an echolink proxy is usually the best alternative.
