L2PT:
https://www.juniper.net/documentation/en_US/junos/topics/concept/l2pt-ex-series.html
Layer 2 protocol tunneling (L2PT) enables service providers to send Layer 2 protocol data units (PDUs) across the provider’s cloud and deliver them to Juniper Networks EX Series Ethernet Switches that are not part of the local broadcast domain.
L2PT and QinQ tunneling
http://nextheader.net/2016/09/09/qinq-and-l2pt-on-junos-els/