Alcatel-Lucent 6850-48 Reference Guide

OmniSwitch CLI Reference Guide

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MPLS forwarding is performed by routers called Label Switching Routers (LSRs). A Label Switched Path 
(LSP) is a path through one or more LSRs. 

There are two types of LSPs that are configurable using MPLS:

• Static LSPs. A Static LSP specifies a statically defined path of LSRs. Configuration of label mappings 

and MPLS actions is required on each router that will participate in the static path. No signaling proto-
col, such as the Label Distribution Protocol (LDP), is required, and there is no dependence on a gate-
way protocol topology or local forwarding table. Static LSPs are able to cross an Autonomous System 
(AS) boundary.

• Signaled LSP. The LSPs are set up using a signaling protocol, such as LDP. The signaling protocol 

allows the automatic assignment of labels from an ingress router to the egress router. Signaling is trig-
gered by the ingress router, therefore configuration is only required on this router. A signaled LSP is 
confined to one gateway protocol area and, therefore, cannot cross an AS boundary. 

In addition to static LSPs, a static Fast Reroute feature is available that allows the configuration of backup 
static LSP tunnels.FRR uses the backup tunnels for alternate routes in the event an LSP goes down.

This chapter provides information about the Command Line Interface (CLI) commands used to configure 
static LSPs and backup static LSPs used by the FRR mechanism. For information about LDP commands 
used to configure signaled LSPs, see 

MIB information for static LSP is as follows:

Filename: TIMETRA-MPLS-MIB.mib
Module: TIMETRA-MPLS-MIB

MIB information for static FRR is as follows:

AlcatelStaticFrr.mib file

ALCATEL-STATIC-FRR-MIB

The following table summarizes the available static LSP and static FRR commands: