R3303-HP HSR6800 Routers MPLS Configuration Guide

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To simplify the configuration, when setting up an LDP LSP across the core layer, you can use the MPLS TE
tunnel that is already established in the core layer. As shown in Figure 23, w
hen using the MPLS TE tunnel
to establish the LDP LSP, you do not need to establish local LDP sessions between neighboring LSRs in the
core layer. All you need to do is to establish a remote session between the ingress node and egress node
of the MPLS TE tunnel. Then, label bindings can be exchanged and an LDP LSP can be established
between the MPLS TE tunnel ingress and egress. The LDP LSP is carried on the MPLS TE tunnel. In this way,
a hierarchical LSP is formed.
Figure 23 Configure an LDP LSP over an MPLS TE LSP
By default, LDP does not advertise any prefix-based label mapping message through a remote session.
To enable LDP to advertise prefix-based labels through a remote session, configure the prefix-label
advertise command. For a description of the prefix-label advertise command, see MPLS Command
Reference.
Protocols and standards
• RFC 2702, Requirements for Traffic Engineering Over MPLS
• RFC 3212, Constraint-Based LSP Setup using LDP
• RFC 2205, Resource ReSerVation Protocol
• RFC 3209, RSVP-TE: Extensions to RSVP for LSP Tunnels
• RFC 2961, RSVP Refresh Overhead Reduction Extensions
• RFC 3564, Requirements for Support of Differentiated Service-aware MPLS Traffic Engineering
• ITU-T Recommendation Y.1720, Protection switching for MPLS networks
MPLS TE configuration task list
Task Remarks
Configuring basic MPLS TE Required.
Configuring DiffServ-aware TE Optional.
Configuring an
Creating an MPLS TE tunnel over a static CR-LSP Required.