Label Stack
VPLS MPLS packets have a two-label stack. The outer label is used for normal MPLS forwarding in the service provider's network. If BGP is used to establish the VPLS, the inner label is allocated by a PE as part of a label block. If LDP is used, the inner label is a virtual circuit ID assigned by LDP when it first established a mesh between the participating PEs. Every PE keeps track of assigned inner label, and associates these with the VPLS instance.
Read more about this topic: Virtual Private LAN Service
Famous quotes containing the words label and/or stack:
“... beauty, like ecstasy, has always been hostile to the commonplace. And the commonplace, under its popular label of the normal, has been the supreme authority for Homo sapiens since the days when he was probably arboreal.”
—Ellen Glasgow (18731945)
“What is a farm but a mute gospel? The chaff and the wheat, weeds and plants, blight, rain, insects, sunit is a sacred emblem from the first furrow of spring to the last stack which the snow of winter overtakes in the fields.”
—Ralph Waldo Emerson (18031882)