A "hub" is a point, on the internet, controlled by Avalon but typically many thousands of miles from the actual game servers in Washington DC. They exist in an effort to offer alternatives, when parts of the internet may be lagged-up; by affording most users of the "hub" an alternate route from their home-location to the Avalon servers.
European Players ("EUROHUB" in Amsterdam, Holland):
South USA/Texas/Mexico ("TEXASHUB" in Dallas TX):
Pacific Coast USA and Canada ("CALIHUB" in San Jose, CA):
Asia/Australia Pacific ("ASIAHUB in Singapore):
Ports can be used include 23 (standard) and, for firewall circumvention:
33, 80, 443, 8080, 8888 and 2323 or 7777