Just a short thought, so maybe I'm wrong. I added some illustrations to it 
"WorldCluster"
The "WorldCluster" is as the name said a cluster of different "complete" world servers. Leaded by one "Main Worldserver" which is connected to the logonserver (Realmlist). The "ClusterServers" are connected and accessable through the main worldserver.

"MapCluster"
The "MapCluster" is a further step. Functions like Raids/Dungeons or Battleground will be handled outside of the main server.

"RealmCluster (Connected Realms)"
The "RealmCluster" or simple "Connected Realms" are linked together through the logonserver. Players from main server A) and main Server B) are ported to theRaids/Dungeons-server ...


The "WorldCluster" is as the name said a cluster of different "complete" world servers. Leaded by one "Main Worldserver" which is connected to the logonserver (Realmlist). The "ClusterServers" are connected and accessable through the main worldserver.
The "MapCluster" is a further step. Functions like Raids/Dungeons or Battleground will be handled outside of the main server.
The "RealmCluster" or simple "Connected Realms" are linked together through the logonserver. Players from main server A) and main Server B) are ported to theRaids/Dungeons-server ...
The post was edited 3 times, last by Tulba ().