The following is from echolink firewall page

Linksys Routers
  1.. Using a Web browser, bring up your router's configuration page.  By
default, the URL is 192.168.1.1, the user name is blank, and the password is
"admin".
  2.. Click the Advanced tab.
  3.. Click the Forwarding tab.
  4.. If you see a column labeled "Customized Applications" on the left,
enter "EchoLink" on the first line.  (Not all versions of the Linksys
firmware have this column.)
  5.. In the first pair of Service Port Range (or Ext.Port) boxes along the
top, enter 5198 and 5199.
  6.. On the same line, under Protocol, choose UDP (or check the UDP box).
  7.. On the same line, enter the local IP address of the computer running
EchoLink.  (If you are not sure what the address is, run "winipcfg" or
"ipconfig" from a command prompt).
  8.. If there is an Enable check box on the same line, check it.
  9.. Click Apply to save changes
Microsoft Windows XP
Windows XP comes with a built-in "firewall" feature that helps protect your
computer from undesired connections from the Internet.  In order to use
EchoLink, you will need to adjust some settings.  The software must be
configured to allow TCP port 5200 to pass outbound, and UDP ports 5198 and
5199 to pass inbound and outbound.

For more information, see Windows XP Firewall Setup.   Also see the
Microsoft article Using the Internet Connection Firewall.

http://www.qsl.net/vk2jtp/xpfirewall.htm
is the link address of windows xp information

Lynn
[log in to unmask]