72
Bypass
tunnel
—An MPLS TE tunnel used to protect a link or node of the primary CRLSP.
•
Point of local repair
—A PLR is the ingress node of the bypass tunnel. It must be located on
the primary CRLSP but must not be the egress node of the primary CRLSP.
•
Merge
point
—An MP is the egress node of the bypass tunnel. It must be located on the primary
CRLSP but must not be the ingress node of the primary CRLSP.
375B
Protection modes
FRR provides the following protection modes:
•
Link
protection
—The PLR and the MP are connected through a direct link and the primary
CRLSP traverses this link. When the link fails, traffic is switched to the bypass tunnel. As shown
in
708H
Figure 26
, the primary CRLSP is Router A—Router B—Router C—Router D, and the bypass
tunnel is Router B—Router F—Router C. This mode is also called next-hop (NHOP) protection.
Figure 26 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
709H
Figure 27
, 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 27 FRR node protection
175B
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 the following DS-TE modes:
•
Prestandard
mode
—Proprietary DS-TE mode of Hewlett Packard Enterprise.