If you are using an AG2 client, it will need to connect to:
port 8000/TCP (Virtual Venue Server port) on the machine hosting the AG2 venue server.
port 8002/TCP (Event port) on the machine hosting the AG2 venue server.
port 8004/TCP (Text port) on the machine hosting the AG2 venue server.
port 8006/TCP (Data port) on the machine hosting the AG2 venue server.
(Note that additional ports must be opened for the video and audio tools. See the sections VIC/IGvideo, RAT/IGaudio and/or Multicast-Unicast bridges)
NB. Note that these ports can be changed at the server side, so always check whether those ports are correct. It is frequent to find servers that listen on ports 9000, 9002, 9004 and 9006.