MPLS consists of 3 components:1. MPLS forwarding2. MPLS signalling3. Mapping layer 3 traffic onto MPLS LSPsThe document mpls-forwarding basics explains item 1.Examples of MPLS signalling protocols are: RSVP-TE LDP and CR-LDP.The package ldp-portable is an implementation of LDP and contains moreinformation about LDP based MPLS signalling.Mapping of layer 3 traffic to MPLS LSPs is accomplised in a couple ofdifferent ways.-Per FEC where FEC is an entry in the routing table-Virtual interface that represents an LSP