Cisco NCS 5500 Series Configuration Manual page 60

Implementing MPLS Traffic Engineering
MPLS-TE Features - Details
The following figure illustrates link protection.
Figure 7: Link Protection
FRR provides node protection for LSPs. Backup tunnels that bypass next-hop nodes along LSP paths are
called next-next-hop (NNHOP) backup tunnels because they terminate at the node following the next-hop
node of the LSP paths, bypassing the next-hop node. They protect LSPs if a node along their path fails by
enabling the node upstream of the failure to reroute the LSPs and their traffic around the failed node to the
next-next hop. NNHOP backup tunnels also provide protection from link failures, because they bypass the
failed link and the node.
The following figure illustrates node protection.
Figure 8: Node Protection
Differentiated Services Traffic Engineering
MPLS Differentiated Services Aware Traffic Engineering (DS-TE) is an extension of the regular MPLS-TE
feature. Regular traffic engineering does not provide bandwidth guarantees to different traffic classes. A single
bandwidth constraint is used in regular TE that is shared by all traffic. To support various classes of service
(CoS), you can configure multiple bandwidth constraints. These bandwidth constraints can be treated differently
based on the requirement for the traffic class using that constraint.
MPLS Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.2.x
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