Label switching and LSP concepts

Label Switched Paths

A Label Switched Path is a unidirectional tunnel through the MPLS network from ingress to egress. LSPs are established before traffic flows, creating a predetermined forwarding path. Each router along the path allocates a local label and installs a mapping in its Label Forwarding Information Base that associates the incoming label with an outgoing label and next-hop interface. Packets entering an LSP are forwarded along this precomputed path without any per-packet routing decisions by intermediate routers, providing predictable latency and simplified forwarding behavior across the transport…