RSVP-TE pop-and-forward LSP tunnels

Pop-and-forward LSPs introduce the notion of pre-installed per traffic engineering link pop labels that are shared by RSVP-TE LSPs that traverse these links. A transit label-switching router (LSR) allocates a unique pop label per traffic engineering link with a forwarding action to pop the label and forward the packet over that traffic engineering link should the label appear at the top of the packet. You can configure pop-and-forward LSPs to significantly reduce the required forwarding plane state, enabling the pop-and-forward tunnels to couple the feature benefits of the RSVP-TE control plane with the simplicity of the shared MPLS forwarding plane. All the existing RSVP-TE functionalities, such as bandwidth admission control, LSP priorities, preemption, auto-bandwidth, and MPLS fast reroute continue to work with pop-and-forward tunnels.