I did a search for JetVision Server and it appears to be some type of Java
based application for managing Voice Over Internet Protocol (VOIP). So I
don't think you installed that software recently.
Based on the symptoms you described it sounds like you would need to open a
port on your firewall for the application. This would be the case if you
recently installed a firewall on your computer (XP Firewall, ZoneAlarm) or
changed your router as some routers have built in firewalls.