VXCs are private, point-to-point, Ethernet pseudo-wires presented as a Layer 2 VLAN between two endpoints. The originating (or A-End) of a VXC is always a port owned by the customer ordering the VXC. The B end can be any of the four destination types that are described in more detail here. All VXCs have a large MTU, support Q-in-Q, and are transparent to most protocols.
Unicast Frame Delivery: Unconditional
VLAN Ethernet Type: 0x8100
Q-in-Q (802.1ad): Supported
Maximum Ethernet Frame Size: 9100 bytes (including Ethernet header, not including FCS)
Layer 2 Control Protocol Transparency:
|STP, MSTP, RSTP, PVST+||Tunnel|