Facebook Autoflex

Hi experts.
Today i read something pretty interesting about Facebook Autoflex.
The solution of this functionality allow carriers to offer to their customers (prepaid or postpaid) usage “Facebook text only” and forbid other media resources (photos, videos, etc).
The input for accessing the free service is through the header enrichment feature. Unfortannelly there is no details about autoflex flow with carrier core network.

Does somebody has implemented Autoflex or know about the logical flow?