Network Interface Types

VPLS instances, like bridge groups, support two types of network interfaces:

Subscriber (client)—A subscriber (client) interface is downstream from the traffic flow; that is, the traffic flow direction is from the server (trunk) to the client (subscriber). This is the default network interface type for both VPLS instances and bridge groups.
Trunk (server)—A trunk (server) interface is upstream from the traffic flow; that is, the traffic flow direction is from the client (subscriber) to the server (trunk). To configure a trunk interface, you must specify the subscriber-trunk keyword as part of the bridge-group command. The VPLS virtual core interface always acts as a trunk interface, and cannot be configured as a subscriber interface.