VMAN
In ExtremeXOS software,
Virtual MANs are a bi-directional virtual data connection that creates a private path
through the public network. One VMAN is completely isolated from other VMANs; the
encapsulation allows the VMAN traffic to be switched over Layer 2 infrastructure. You
implement VMAN using an additional 892.1Q tag and a configurable EtherType; this feature is
also known as Q-in-Q switching.