EchoLink requires that your router or firewall allow inbound and
outbound UDP to destination ports 5198 and 5199, and outbound TCP to
port 5200. Source ports are dynamically assigned. If you are using a
home-network router, you will also need to configure the router to
"forward" UDP ports 5198 and 5199 to the PC on which EchoLink is
running.

See http://www.echolink.org/firewall_solutions.htm


On Wed, 17 Aug 2005 16:15:52 -0700, "tubeham"
wrote:

I am trying to help a friend get started on Echolink. He uses AT&T as a
dialup provider. Does AT&T support the protocols required to make
Echolink work?

Thanks