HP HPE FlexNetwork MSR Router Series, Configuration Manual, Page: 88 / 594

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Figure 28 FRR link protection
•
Node protection —The PLR and the MP are connected through a device and the primary
CRLSP traverses this device. When the device fails, traffic is switched to the bypass tunnel. As
shown in
Figure 29 , the primary CRLSP is Router A—Router B—Router C—Router D—Router
E, and the bypass tunnel is Router B—Router F—Router D. Router C is the protected device.
This mode is also called next-next-hop (NNHOP) protection.
Figure 29 FRR node protection
DiffServ-aware TE
DiffServ is a model that provides differentiated QoS guarantees based on class of service. MPLS TE
is a traffic engineering solution that focuses on optimizing network resources allocation.
DiffServ-aware TE (DS-TE) combines DiffServ and TE to optimize network resources allocation on a
per-service class basis. DS-TE defines different bandwidth constraints for class types. It maps each
traffic class type to the CRLSP that is constraint-compliant for the class type.
The device supports these DS-TE modes:
•
Prestandard mode —Hewlett Packard Enterprise proprietary DS-TE.
•
IETF mode —Complies with RFC 4124, RFC 4125, and RFC 4127.
Basic concepts
•
CT —Class Type. DS-TE allocates link bandwidth, implements constraint-based routing, and
performs admission control on a per-class type basis. A given traffic flow belongs to the same
CT on all links.
•
BC —Bandwidth Constraint. BC restricts the bandwidth for one or more CTs.
•
Bandwidth constraint model —Algorithm for implementing bandwidth constraints on different
CTs. A BC model comprises two factors, the maximum number of BCs (MaxBC) and the
mappings between BCs and CTs. DS-TE supports two BC models, Russian Dolls Model (RDM)
and Maximum Allocation Model (MAM).