Sharing permissions across the network?

Hey,

How do I use the plugin on a "global" scope instead of a "local" one?

I've created subscriptions and access levels on the root site and I want those same permissions to be the "law" throughout the whole network.

However, I have to enable the plugin on a per site basis and each site is ignorant as to the other sites permissions.

The model I'm following is

-> User signs up on root site
-> User chooses subscription plan
-> Based on subscription, user is granted access to child/other network sites.

Thanks!!