MEF 26.1 expands the basic model (described in MEF 10.x) to facilitate the cases where the service spans multiple Carrier Ethernet Networks (CEN) operated by different administrative entities.
Each CEN is managed by an Operator where the Operator provides connectivity services to the Service Providerthat in turn provides the UNI-to-UNI (end-to-end service) to the Subscriber(as described in the MEF 10.x model)