Mpls Network Structure; Lsp Establishment And Label Distribution - HP 12500 Series Configuration Manual

MPLS network structure

Figure 3 Diagram for the MPLS network structure
As shown in
An MPLS domain consists of the following types of LSRs:
• Ingress LSRs receive and label packets coming into the MPLS domain.
Transit LSRs forward packets along LSPs to their egress LERs according to the labels.
•
Egress LSRs remove labels from packets and forward the packets to their destination networks.
•

LSP establishment and label distribution

LSP establishment
Establishing LSPs is to bind FECs with labels on each LSR involved and notify its adjacent LSRs of the
bindings, so as to establish the LFIB on each LSR. LSPs can be manually established through configuration,
or dynamically established through label distribution protocols.
Establishing a static LSP through manual configuration
•
To establish a static LSP, you must assign a label to the FEC on each LSR along the packet
forwarding path. Establishment of static LSPs consumes fewer resources than dynamic LSP
establishment. However, static LSPs cannot adapt to network topology changes. Therefore, static
LSPs are suitable for small-scale networks with simple, stable topologies.
Establishing an LSP through a label distribution protocol
•
Label distribution protocols are MPLS signaling protocols. They can classify FECs, distribute labels,
and establish and maintain LSPs. Label distribution protocols include protocols designed
specifically for label distribution, such as the Label Distribution Protocol (LDP), and protocols
extended to support label distribution, such as BGP and RSVP-TE.
This document discusses LDP only. For more information about LDP, see "LDP."
NOTE:
In this document, the term
LDP
term refers to the Label Distribution Protocol defined in RFC 5036.
Figure 3, LSRs in the same routing or administrative domain form an MPLS domain.
label distribution protocols
represents all protocols for label distribution, and the
3