To use Zone Alarm Pro with EchoLink ... see below

Zone Alarm Help states .... 

"To use Voice over IP (VOIP) programs with ZoneAlarm, you must give the VOIP application server permission and access permission.)

To use Zone Alarm (Free Version) with EchoLink.

Select "Firewall" on the left of the Zone Alarm Screen.

Set Internet Zone Security Slider to Medium

Zone Alarm Pro

Select "Firewall" on left of screen and set "Internet Zone Security" to "High" and Click "Custom"

Under the heading "High security settings for internet zone"

Select the checkbox "Allow incoming UDP ports"

In the dialog box then presented at the bottom on this screen enter 5198-5199

Select the checkbox "Allow outgoing UDP ports"

In the dialog box then presented at the bottom on this screen enter 5198-5199

Select the checkbox "Allow outgoing TCP ports"

In the dialog box then presented at the bottom on this screen enter 5200

Click Apply, Ok.