I have always registered all my devices to pbxes.org
A few days ago I lost registration (only from my freepbx trying to register to a subPBX on pbxes.org).
Searching in the forum I found a thread (on trixbox) which suggested registering to www2.pbxes.com (in my case that would be www3 but that's just detail). When I changed the "host=" entry and the registration string as suggested, my freepbx successfully registered.
I'm worried that this method might not always work since pbxes.org should redirect to the appropriate host.
Please clarify or point me to any documentation that does.